_

_

new _(value) → {Object}

Description:
  • Creates a `lodash` object which wraps `value` to enable implicit method chain sequences. Methods that operate on and return arrays, collections, and functions can be chained together. Methods that retrieve a single value or may return a primitive value will automatically end the chain sequence and return the unwrapped value. Otherwise, the value must be unwrapped with `_#value`. Explicit chain sequences, which must be unwrapped with `_#value`, may be enabled using `_.chain`. The execution of chained methods is lazy, that is, it's deferred until `_#value` is implicitly or explicitly called. Lazy evaluation allows several methods to support shortcut fusion. Shortcut fusion is an optimization to merge iteratee calls; this avoids the creation of intermediate arrays and can greatly reduce the number of iteratee executions. Sections of a chain sequence qualify for shortcut fusion if the section is applied to an array and iteratees accept only one argument. The heuristic for whether a section qualifies for shortcut fusion is subject to change. Chaining is supported in custom builds as long as the `_#value` method is directly or indirectly included in the build. In addition to lodash methods, wrappers have `Array` and `String` methods. The wrapper `Array` methods are: `concat`, `join`, `pop`, `push`, `shift`, `sort`, `splice`, and `unshift` The wrapper `String` methods are: `replace` and `split` The wrapper methods that support shortcut fusion are: `at`, `compact`, `drop`, `dropRight`, `dropWhile`, `filter`, `find`, `findLast`, `head`, `initial`, `last`, `map`, `reject`, `reverse`, `slice`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, and `toArray` The chainable wrapper methods are: `after`, `ary`, `assign`, `assignIn`, `assignInWith`, `assignWith`, `at`, `before`, `bind`, `bindAll`, `bindKey`, `castArray`, `chain`, `chunk`, `commit`, `compact`, `concat`, `conforms`, `constant`, `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`, `defer`, `delay`, `difference`, `differenceBy`, `differenceWith`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `extend`, `extendWith`, `fill`, `filter`, `flatMap`, `flatMapDeep`, `flatMapDepth`, `flatten`, `flattenDeep`, `flattenDepth`, `flip`, `flow`, `flowRight`, `fromPairs`, `functions`, `functionsIn`, `groupBy`, `initial`, `intersection`, `intersectionBy`, `intersectionWith`, `invert`, `invertBy`, `invokeMap`, `iteratee`, `keyBy`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, `matchesProperty`, `memoize`, `merge`, `mergeWith`, `method`, `methodOf`, `mixin`, `negate`, `nthArg`, `omit`, `omitBy`, `once`, `orderBy`, `over`, `overArgs`, `overEvery`, `overSome`, `partial`, `partialRight`, `partition`, `pick`, `pickBy`, `plant`, `property`, `propertyOf`, `pull`, `pullAll`, `pullAllBy`, `pullAllWith`, `pullAt`, `push`, `range`, `rangeRight`, `rearg`, `reject`, `remove`, `rest`, `reverse`, `sampleSize`, `set`, `setWith`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`, `spread`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`, `thru`, `toArray`, `toPairs`, `toPairsIn`, `toPath`, `toPlainObject`, `transform`, `unary`, `union`, `unionBy`, `unionWith`, `uniq`, `uniqBy`, `uniqWith`, `unset`, `unshift`, `unzip`, `unzipWith`, `update`, `updateWith`, `values`, `valuesIn`, `without`, `wrap`, `xor`, `xorBy`, `xorWith`, `zip`, `zipObject`, `zipObjectDeep`, and `zipWith` The wrapper methods that are **not** chainable by default are: `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clamp`, `clone`, `cloneDeep`, `cloneDeepWith`, `cloneWith`, `conformsTo`, `deburr`, `defaultTo`, `divide`, `each`, `eachRight`, `endsWith`, `eq`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `first`, `floor`, `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, `get`, `gt`, `gte`, `has`, `hasIn`, `head`, `identity`, `includes`, `indexOf`, `inRange`, `invoke`, `isArguments`, `isArray`, `isArrayBuffer`, `isArrayLike`, `isArrayLikeObject`, `isBoolean`, `isBuffer`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isEqualWith`, `isError`, `isFinite`, `isFunction`, `isInteger`, `isLength`, `isMap`, `isMatch`, `isMatchWith`, `isNaN`, `isNative`, `isNil`, `isNull`, `isNumber`, `isObject`, `isObjectLike`, `isPlainObject`, `isRegExp`, `isSafeInteger`, `isSet`, `isString`, `isUndefined`, `isTypedArray`, `isWeakMap`, `isWeakSet`, `join`, `kebabCase`, `last`, `lastIndexOf`, `lowerCase`, `lowerFirst`, `lt`, `lte`, `max`, `maxBy`, `mean`, `meanBy`, `min`, `minBy`, `multiply`, `noConflict`, `noop`, `now`, `nth`, `pad`, `padEnd`, `padStart`, `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `sample`, `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedIndexBy`, `sortedLastIndex`, `sortedLastIndexBy`, `startCase`, `startsWith`, `stubArray`, `stubFalse`, `stubObject`, `stubString`, `stubTrue`, `subtract`, `sum`, `sumBy`, `template`, `times`, `toFinite`, `toInteger`, `toJSON`, `toLength`, `toLower`, `toNumber`, `toSafeInteger`, `toString`, `toUpper`, `trim`, `trimEnd`, `trimStart`, `truncate`, `unescape`, `uniqueId`, `upperCase`, `upperFirst`, `value`, and `words`
Source:
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2, 3]);

// Returns an unwrapped value.
wrapped.reduce(_.add);
// => 6

// Returns a wrapped value.
var squares = wrapped.map(square);

_.isArray(squares);
// => false

_.isArray(squares.value());
// => true
Parameters:
Name Type Description
value * The value to wrap in a `lodash` instance.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

Members

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) iteratee

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keys

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']

(static) keysIn

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) now

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) templateSettings :Object

Description:
  • By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Source:
By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Type:
  • Object

(static) toInteger

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3

(static) toNumber

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Converts `value` to a number.
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

Methods

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) now() → {number}

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.
Returns:
Returns the timestamp.
Type
number

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) runInContext(contextopt) → {function}

Description:
  • Create a new pristine `lodash` function using the `context` object.
Source:
Since:
  • 1.1.0
Example
_.mixin({ 'foo': _.constant('foo') });

var lodash = _.runInContext();
lodash.mixin({ 'bar': lodash.constant('bar') });

_.isFunction(_.foo);
// => true
_.isFunction(_.bar);
// => false

lodash.isFunction(lodash.foo);
// => false
lodash.isFunction(lodash.bar);
// => true

// Create a suped-up `defer` in Node.js.
var defer = _.runInContext({ 'setTimeout': setImmediate }).defer;
Parameters:
Name Type Attributes Default Description
context Object <optional>
root The context object.
Returns:
Returns a new `lodash` function.
Type
function

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) sortBy(collection, …iterateesopt) → {Array}

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees function | Array:.<function()> <optional>
<repeatable>
[_.identity] The iteratees to sort by.
Returns:
Returns the new sorted array.
Type
Array

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'lodash.templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

_

new _(value) → {Object}

Description:
  • Creates a `lodash` object which wraps `value` to enable implicit method chain sequences. Methods that operate on and return arrays, collections, and functions can be chained together. Methods that retrieve a single value or may return a primitive value will automatically end the chain sequence and return the unwrapped value. Otherwise, the value must be unwrapped with `_#value`. Explicit chain sequences, which must be unwrapped with `_#value`, may be enabled using `_.chain`. The execution of chained methods is lazy, that is, it's deferred until `_#value` is implicitly or explicitly called. Lazy evaluation allows several methods to support shortcut fusion. Shortcut fusion is an optimization to merge iteratee calls; this avoids the creation of intermediate arrays and can greatly reduce the number of iteratee executions. Sections of a chain sequence qualify for shortcut fusion if the section is applied to an array and iteratees accept only one argument. The heuristic for whether a section qualifies for shortcut fusion is subject to change. Chaining is supported in custom builds as long as the `_#value` method is directly or indirectly included in the build. In addition to lodash methods, wrappers have `Array` and `String` methods. The wrapper `Array` methods are: `concat`, `join`, `pop`, `push`, `shift`, `sort`, `splice`, and `unshift` The wrapper `String` methods are: `replace` and `split` The wrapper methods that support shortcut fusion are: `at`, `compact`, `drop`, `dropRight`, `dropWhile`, `filter`, `find`, `findLast`, `head`, `initial`, `last`, `map`, `reject`, `reverse`, `slice`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, and `toArray` The chainable wrapper methods are: `after`, `ary`, `assign`, `assignIn`, `assignInWith`, `assignWith`, `at`, `before`, `bind`, `bindAll`, `bindKey`, `castArray`, `chain`, `chunk`, `commit`, `compact`, `concat`, `conforms`, `constant`, `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`, `defer`, `delay`, `difference`, `differenceBy`, `differenceWith`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `extend`, `extendWith`, `fill`, `filter`, `flatMap`, `flatMapDeep`, `flatMapDepth`, `flatten`, `flattenDeep`, `flattenDepth`, `flip`, `flow`, `flowRight`, `fromPairs`, `functions`, `functionsIn`, `groupBy`, `initial`, `intersection`, `intersectionBy`, `intersectionWith`, `invert`, `invertBy`, `invokeMap`, `iteratee`, `keyBy`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, `matchesProperty`, `memoize`, `merge`, `mergeWith`, `method`, `methodOf`, `mixin`, `negate`, `nthArg`, `omit`, `omitBy`, `once`, `orderBy`, `over`, `overArgs`, `overEvery`, `overSome`, `partial`, `partialRight`, `partition`, `pick`, `pickBy`, `plant`, `property`, `propertyOf`, `pull`, `pullAll`, `pullAllBy`, `pullAllWith`, `pullAt`, `push`, `range`, `rangeRight`, `rearg`, `reject`, `remove`, `rest`, `reverse`, `sampleSize`, `set`, `setWith`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`, `spread`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`, `thru`, `toArray`, `toPairs`, `toPairsIn`, `toPath`, `toPlainObject`, `transform`, `unary`, `union`, `unionBy`, `unionWith`, `uniq`, `uniqBy`, `uniqWith`, `unset`, `unshift`, `unzip`, `unzipWith`, `update`, `updateWith`, `values`, `valuesIn`, `without`, `wrap`, `xor`, `xorBy`, `xorWith`, `zip`, `zipObject`, `zipObjectDeep`, and `zipWith` The wrapper methods that are **not** chainable by default are: `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clamp`, `clone`, `cloneDeep`, `cloneDeepWith`, `cloneWith`, `conformsTo`, `deburr`, `defaultTo`, `divide`, `each`, `eachRight`, `endsWith`, `eq`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `first`, `floor`, `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, `get`, `gt`, `gte`, `has`, `hasIn`, `head`, `identity`, `includes`, `indexOf`, `inRange`, `invoke`, `isArguments`, `isArray`, `isArrayBuffer`, `isArrayLike`, `isArrayLikeObject`, `isBoolean`, `isBuffer`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isEqualWith`, `isError`, `isFinite`, `isFunction`, `isInteger`, `isLength`, `isMap`, `isMatch`, `isMatchWith`, `isNaN`, `isNative`, `isNil`, `isNull`, `isNumber`, `isObject`, `isObjectLike`, `isPlainObject`, `isRegExp`, `isSafeInteger`, `isSet`, `isString`, `isUndefined`, `isTypedArray`, `isWeakMap`, `isWeakSet`, `join`, `kebabCase`, `last`, `lastIndexOf`, `lowerCase`, `lowerFirst`, `lt`, `lte`, `max`, `maxBy`, `mean`, `meanBy`, `min`, `minBy`, `multiply`, `noConflict`, `noop`, `now`, `nth`, `pad`, `padEnd`, `padStart`, `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `sample`, `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedIndexBy`, `sortedLastIndex`, `sortedLastIndexBy`, `startCase`, `startsWith`, `stubArray`, `stubFalse`, `stubObject`, `stubString`, `stubTrue`, `subtract`, `sum`, `sumBy`, `template`, `times`, `toFinite`, `toInteger`, `toJSON`, `toLength`, `toLower`, `toNumber`, `toSafeInteger`, `toString`, `toUpper`, `trim`, `trimEnd`, `trimStart`, `truncate`, `unescape`, `uniqueId`, `upperCase`, `upperFirst`, `value`, and `words`
Source:
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2, 3]);

// Returns an unwrapped value.
wrapped.reduce(_.add);
// => 6

// Returns a wrapped value.
var squares = wrapped.map(square);

_.isArray(squares);
// => false

_.isArray(squares.value());
// => true
Parameters:
Name Type Description
value * The value to wrap in a `lodash` instance.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

Members

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) iteratee

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keys

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']

(static) keysIn

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) now

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) templateSettings :Object

Description:
  • By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Source:
By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Type:
  • Object

(static) toInteger

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3

(static) toNumber

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Converts `value` to a number.
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

Methods

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) now() → {number}

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.
Returns:
Returns the timestamp.
Type
number

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) runInContext(contextopt) → {function}

Description:
  • Create a new pristine `lodash` function using the `context` object.
Source:
Since:
  • 1.1.0
Example
_.mixin({ 'foo': _.constant('foo') });

var lodash = _.runInContext();
lodash.mixin({ 'bar': lodash.constant('bar') });

_.isFunction(_.foo);
// => true
_.isFunction(_.bar);
// => false

lodash.isFunction(lodash.foo);
// => false
lodash.isFunction(lodash.bar);
// => true

// Create a suped-up `defer` in Node.js.
var defer = _.runInContext({ 'setTimeout': setImmediate }).defer;
Parameters:
Name Type Attributes Default Description
context Object <optional>
root The context object.
Returns:
Returns a new `lodash` function.
Type
function

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) sortBy(collection, …iterateesopt) → {Array}

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees function | Array:.<function()> <optional>
<repeatable>
[_.identity] The iteratees to sort by.
Returns:
Returns the new sorted array.
Type
Array

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'lodash.templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

_

new _(value) → {Object}

Description:
  • Creates a `lodash` object which wraps `value` to enable implicit method chain sequences. Methods that operate on and return arrays, collections, and functions can be chained together. Methods that retrieve a single value or may return a primitive value will automatically end the chain sequence and return the unwrapped value. Otherwise, the value must be unwrapped with `_#value`. Explicit chain sequences, which must be unwrapped with `_#value`, may be enabled using `_.chain`. The execution of chained methods is lazy, that is, it's deferred until `_#value` is implicitly or explicitly called. Lazy evaluation allows several methods to support shortcut fusion. Shortcut fusion is an optimization to merge iteratee calls; this avoids the creation of intermediate arrays and can greatly reduce the number of iteratee executions. Sections of a chain sequence qualify for shortcut fusion if the section is applied to an array and iteratees accept only one argument. The heuristic for whether a section qualifies for shortcut fusion is subject to change. Chaining is supported in custom builds as long as the `_#value` method is directly or indirectly included in the build. In addition to lodash methods, wrappers have `Array` and `String` methods. The wrapper `Array` methods are: `concat`, `join`, `pop`, `push`, `shift`, `sort`, `splice`, and `unshift` The wrapper `String` methods are: `replace` and `split` The wrapper methods that support shortcut fusion are: `at`, `compact`, `drop`, `dropRight`, `dropWhile`, `filter`, `find`, `findLast`, `head`, `initial`, `last`, `map`, `reject`, `reverse`, `slice`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, and `toArray` The chainable wrapper methods are: `after`, `ary`, `assign`, `assignIn`, `assignInWith`, `assignWith`, `at`, `before`, `bind`, `bindAll`, `bindKey`, `castArray`, `chain`, `chunk`, `commit`, `compact`, `concat`, `conforms`, `constant`, `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`, `defer`, `delay`, `difference`, `differenceBy`, `differenceWith`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `extend`, `extendWith`, `fill`, `filter`, `flatMap`, `flatMapDeep`, `flatMapDepth`, `flatten`, `flattenDeep`, `flattenDepth`, `flip`, `flow`, `flowRight`, `fromPairs`, `functions`, `functionsIn`, `groupBy`, `initial`, `intersection`, `intersectionBy`, `intersectionWith`, `invert`, `invertBy`, `invokeMap`, `iteratee`, `keyBy`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, `matchesProperty`, `memoize`, `merge`, `mergeWith`, `method`, `methodOf`, `mixin`, `negate`, `nthArg`, `omit`, `omitBy`, `once`, `orderBy`, `over`, `overArgs`, `overEvery`, `overSome`, `partial`, `partialRight`, `partition`, `pick`, `pickBy`, `plant`, `property`, `propertyOf`, `pull`, `pullAll`, `pullAllBy`, `pullAllWith`, `pullAt`, `push`, `range`, `rangeRight`, `rearg`, `reject`, `remove`, `rest`, `reverse`, `sampleSize`, `set`, `setWith`, `shuffle`, `slice`, `sort`, `sortBy`, `splice`, `spread`, `tail`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `tap`, `throttle`, `thru`, `toArray`, `toPairs`, `toPairsIn`, `toPath`, `toPlainObject`, `transform`, `unary`, `union`, `unionBy`, `unionWith`, `uniq`, `uniqBy`, `uniqWith`, `unset`, `unshift`, `unzip`, `unzipWith`, `update`, `updateWith`, `values`, `valuesIn`, `without`, `wrap`, `xor`, `xorBy`, `xorWith`, `zip`, `zipObject`, `zipObjectDeep`, and `zipWith` The wrapper methods that are **not** chainable by default are: `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clamp`, `clone`, `cloneDeep`, `cloneDeepWith`, `cloneWith`, `conformsTo`, `deburr`, `defaultTo`, `divide`, `each`, `eachRight`, `endsWith`, `eq`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `first`, `floor`, `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, `get`, `gt`, `gte`, `has`, `hasIn`, `head`, `identity`, `includes`, `indexOf`, `inRange`, `invoke`, `isArguments`, `isArray`, `isArrayBuffer`, `isArrayLike`, `isArrayLikeObject`, `isBoolean`, `isBuffer`, `isDate`, `isElement`, `isEmpty`, `isEqual`, `isEqualWith`, `isError`, `isFinite`, `isFunction`, `isInteger`, `isLength`, `isMap`, `isMatch`, `isMatchWith`, `isNaN`, `isNative`, `isNil`, `isNull`, `isNumber`, `isObject`, `isObjectLike`, `isPlainObject`, `isRegExp`, `isSafeInteger`, `isSet`, `isString`, `isUndefined`, `isTypedArray`, `isWeakMap`, `isWeakSet`, `join`, `kebabCase`, `last`, `lastIndexOf`, `lowerCase`, `lowerFirst`, `lt`, `lte`, `max`, `maxBy`, `mean`, `meanBy`, `min`, `minBy`, `multiply`, `noConflict`, `noop`, `now`, `nth`, `pad`, `padEnd`, `padStart`, `parseInt`, `pop`, `random`, `reduce`, `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `sample`, `shift`, `size`, `snakeCase`, `some`, `sortedIndex`, `sortedIndexBy`, `sortedLastIndex`, `sortedLastIndexBy`, `startCase`, `startsWith`, `stubArray`, `stubFalse`, `stubObject`, `stubString`, `stubTrue`, `subtract`, `sum`, `sumBy`, `template`, `times`, `toFinite`, `toInteger`, `toJSON`, `toLength`, `toLower`, `toNumber`, `toSafeInteger`, `toString`, `toUpper`, `trim`, `trimEnd`, `trimStart`, `truncate`, `unescape`, `uniqueId`, `upperCase`, `upperFirst`, `value`, and `words`
Source:
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2, 3]);

// Returns an unwrapped value.
wrapped.reduce(_.add);
// => 6

// Returns a wrapped value.
var squares = wrapped.map(square);

_.isArray(squares);
// => false

_.isArray(squares.value());
// => true
Parameters:
Name Type Description
value * The value to wrap in a `lodash` instance.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

Members

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) add

Description:
  • Adds two numbers.
Source:
Since:
  • 3.4.0
Adds two numbers.
Example
_.add(6, 4);
// => 10

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assign

Description:
  • Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Source:
Since:
  • 0.10.0
See:
  • _.assignIn
Assigns own enumerable string keyed properties of source objects to the destination object. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object` and is loosely based on [`Object.assign`](https://mdn.io/Object/assign).
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assign({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'c': 3 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) assignWith

Description:
  • This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
  • _.assignInWith
This method is like `_.assign` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) at

Description:
  • Creates an array of values corresponding to `paths` of `object`.
Source:
Since:
  • 1.0.0
Creates an array of values corresponding to `paths` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_.at(object, ['a[0].b.c', 'a[1]']);
// => [3, 4]

(static) at

Description:
  • This method is the wrapper version of `_.at`.
Source:
Since:
  • 1.0.0
This method is the wrapper version of `_.at`.
Example
var object = { 'a': [{ 'b': { 'c': 3 } }, 4] };

_(object).at(['a[0].b.c', 'a[1]']).value();
// => [3, 4]

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) attempt

Description:
  • Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 3.0.0
Attempts to invoke `func`, returning either the result or the caught error object. Any additional arguments are provided to `func` when it's invoked.
Example
// Avoid throwing errors for invalid selectors.
var elements = _.attempt(function(selector) {
  return document.querySelectorAll(selector);
}, '>_>');

if (_.isError(elements)) {
  elements = [];
}

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bind

Description:
  • Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives. The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.
Example
function greet(greeting, punctuation) {
  return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, object, 'hi');
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, object, _, '!');
bound('hi');
// => 'hi fred!'

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindAll

Description:
  • Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Source:
Since:
  • 0.1.0
Binds methods of an object to the object itself, overwriting the existing method. **Note:** This method doesn't set the "length" property of bound functions.
Example
var view = {
  'label': 'docs',
  'click': function() {
    console.log('clicked ' + this.label);
  }
};

_.bindAll(view, ['click']);
jQuery(element).on('click', view.click);
// => Logs 'clicked docs' when clicked.

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) bindKey

Description:
  • Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Source:
Since:
  • 0.10.0
Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives. This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) for more details. The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.
Example
var object = {
  'user': 'fred',
  'greet': function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};

var bound = _.bindKey(object, 'greet', 'hi');
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
  return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, 'greet', _, '!');
bound('hi');
// => 'hiya fred!'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) camelCase

Description:
  • Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Source:
Since:
  • 3.0.0
Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase).
Example
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) ceil

Description:
  • Computes `number` rounded up to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded up to `precision`.
Example
_.ceil(4.006);
// => 5

_.ceil(6.004, 2);
// => 6.01

_.ceil(6040, -2);
// => 6100

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) chain

Description:
  • Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Source:
Since:
  • 0.1.0
Creates a `lodash` wrapper instance with explicit method chain sequences enabled.
Example
var users = [
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 }
];

// A sequence without explicit chaining.
_(users).head();
// => { 'user': 'barney', 'age': 36 }

// A sequence with explicit chaining.
_(users)
  .chain()
  .head()
  .pick('user')
  .value();
// => { 'user': 'barney' }

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) commit

Description:
  • Executes the chain sequence and returns the wrapped result.
Source:
Since:
  • 3.2.0
Executes the chain sequence and returns the wrapped result.
Example
var array = [1, 2];
var wrapped = _(array).push(3);

console.log(array);
// => [1, 2]

wrapped = wrapped.commit();
console.log(array);
// => [1, 2, 3]

wrapped.last();
// => 3

console.log(array);
// => [1, 2, 3]

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) countBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.5.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).
Example
_.countBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaults

Description:
  • Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Source:
Since:
  • 0.1.0
See:
Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to `undefined`. Source objects are applied from left to right. Once a property is set, additional values of the same property are ignored. **Note:** This method mutates `object`.
Example
_.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defaultsDeep

Description:
  • This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Source:
Since:
  • 3.10.0
See:
This method is like `_.defaults` except that it recursively assigns default properties. **Note:** This method mutates `object`.
Example
_.defaultsDeep({ 'a': { 'b': 2 } }, { 'a': { 'b': 1, 'c': 3 } });
// => { 'a': { 'b': 2, 'c': 3 } }

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) defer

Description:
  • Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.
Example
_.defer(function(text) {
  console.log(text);
}, 'deferred');
// => Logs 'deferred' after one millisecond.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) delay

Description:
  • Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Source:
Since:
  • 0.1.0
Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.
Example
_.delay(function(text) {
  console.log(text);
}, 1000, 'later');
// => Logs 'later' after one second.

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) difference

Description:
  • Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.without, _.xor
Creates an array of `array` values not included in the other given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array. **Note:** Unlike `_.pullAll`, this method returns a new array.
Example
_.difference([2, 1], [2, 3]);
// => [1]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceBy

Description:
  • This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.pullAllBy`, this method returns a new array.
Example
_.differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) differenceWith

Description:
  • This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Source:
Since:
  • 4.0.0
This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.pullAllWith`, this method returns a new array.
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(objects, [{ 'x': 1, 'y': 2 }], _.isEqual);
// => [{ 'x': 2, 'y': 1 }]

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) divide

Description:
  • Divide two numbers.
Source:
Since:
  • 4.7.0
Divide two numbers.
Example
_.divide(6, 4);
// => 1.5

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entries

Description:
  • Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairs(new Foo);
// => [['a', 1], ['b', 2]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) entriesIn

Description:
  • Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Source:
Since:
  • 4.0.0
Creates an array of own and inherited enumerable string keyed-value pairs for `object` which can be consumed by `_.fromPairs`. If `object` is a map or set, its entries are returned.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.toPairsIn(new Foo);
// => [['a', 1], ['b', 2], ['c', 3]] (iteration order is not guaranteed)

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extend

Description:
  • This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assign` except that it iterates over own and inherited source properties. **Note:** This method mutates `object`.
Example
function Foo() {
  this.a = 1;
}

function Bar() {
  this.c = 3;
}

Foo.prototype.b = 2;
Bar.prototype.d = 4;

_.assignIn({ 'a': 0 }, new Foo, new Bar);
// => { 'a': 1, 'b': 2, 'c': 3, 'd': 4 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) extendWith

Description:
  • This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
See:
This method is like `_.assignIn` except that it accepts `customizer` which is invoked to produce the assigned values. If `customizer` returns `undefined`, assignment is handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, key, object, source). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  return _.isUndefined(objValue) ? srcValue : objValue;
}

var defaults = _.partialRight(_.assignInWith, customizer);

defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
// => { 'a': 1, 'b': 2 }

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) find

Description:
  • Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': true },
  { 'user': 'fred',    'age': 40, 'active': false },
  { 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(users, function(o) { return o.age < 40; });
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find(users, { 'age': 1, 'active': true });
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(users, ['active', false]);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find(users, 'active');
// => object for 'barney'

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) findLast

Description:
  • This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
This method is like `_.find` except that it iterates over elements of `collection` from right to left.
Example
_.findLast([1, 2, 3, 4], function(n) {
  return n % 2 == 1;
});
// => 3

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) floor

Description:
  • Computes `number` rounded down to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded down to `precision`.
Example
_.floor(4.006);
// => 4

_.floor(0.046, 2);
// => 0.04

_.floor(4060, -2);
// => 4000

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flow

Description:
  • Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Source:
Since:
  • 3.0.0
See:
Creates a function that returns the result of invoking the given functions with the `this` binding of the created function, where each successive invocation is supplied the return value of the previous.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flow([_.add, square]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) flowRight

Description:
  • This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Source:
Since:
  • 3.0.0
See:
This method is like `_.flow` except that it creates a function that invokes the given functions from right to left.
Example
function square(n) {
  return n * n;
}

var addSquare = _.flowRight([square, _.add]);
addSquare(1, 2);
// => 9

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) groupBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
_.groupBy([6.1, 4.2, 6.3], Math.floor);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gt

Description:
  • Checks if `value` is greater than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than `other`.
Example
_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) gte

Description:
  • Checks if `value` is greater than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is greater than or equal to `other`.
Example
_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersection

Description:
  • Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Source:
Since:
  • 0.1.0
Creates an array of unique values that are included in all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. The order and references of result values are determined by the first array.
Example
_.intersection([2, 1], [2, 3]);
// => [2]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionBy

Description:
  • This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument: (value).
Example
_.intersectionBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) intersectionWith

Description:
  • This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }]

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invert

Description:
  • Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Source:
Since:
  • 0.7.0
Creates an object composed of the inverted keys and values of `object`. If `object` contains duplicate values, subsequent values overwrite property assignments of previous values.
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invert(object);
// => { '1': 'c', '2': 'b' }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invertBy

Description:
  • This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.1.0
This method is like `_.invert` except that the inverted object is generated from the results of running each element of `object` thru `iteratee`. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).
Example
var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invoke

Description:
  • Invokes the method at `path` of `object`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of `object`.
Example
var object = { 'a': [{ 'b': { 'c': [1, 2, 3, 4] } }] };

_.invoke(object, 'a[0].b.c.slice', 1, 3);
// => [2, 3]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) invokeMap

Description:
  • Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Source:
Since:
  • 4.0.0
Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.
Example
_.invokeMap([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArguments

Description:
  • Checks if `value` is likely an `arguments` object.
Source:
Since:
  • 0.1.0
Checks if `value` is likely an `arguments` object.
Example
_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArray

Description:
  • Checks if `value` is classified as an `Array` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as an `Array` object.
Example
_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isArrayBuffer

Description:
  • Checks if `value` is classified as an `ArrayBuffer` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as an `ArrayBuffer` object.
Example
_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isBuffer

Description:
  • Checks if `value` is a buffer.
Source:
Since:
  • 4.3.0
Checks if `value` is a buffer.
Example
_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isDate

Description:
  • Checks if `value` is classified as a `Date` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `Date` object.
Example
_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isMap

Description:
  • Checks if `value` is classified as a `Map` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Map` object.
Example
_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isRegExp

Description:
  • Checks if `value` is classified as a `RegExp` object.
Source:
Since:
  • 0.1.0
Checks if `value` is classified as a `RegExp` object.
Example
_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isSet

Description:
  • Checks if `value` is classified as a `Set` object.
Source:
Since:
  • 4.3.0
Checks if `value` is classified as a `Set` object.
Example
_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) isTypedArray

Description:
  • Checks if `value` is classified as a typed array.
Source:
Since:
  • 3.0.0
Checks if `value` is classified as a typed array.
Example
_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false

(static) iteratee

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) kebabCase

Description:
  • Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Source:
Since:
  • 3.0.0
Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles).
Example
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keyBy

Description:
  • Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).
Example
var array = [
  { 'dir': 'left', 'code': 97 },
  { 'dir': 'right', 'code': 100 }
];

_.keyBy(array, function(o) {
  return String.fromCharCode(o.code);
});
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy(array, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }

(static) keys

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']

(static) keysIn

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerCase

Description:
  • Converts `string`, as space separated words, to lower case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to lower case.
Example
_.lowerCase('--Foo-Bar--');
// => 'foo bar'

_.lowerCase('fooBar');
// => 'foo bar'

_.lowerCase('__FOO_BAR__');
// => 'foo bar'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lowerFirst

Description:
  • Converts the first character of `string` to lower case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to lower case.
Example
_.lowerFirst('Fred');
// => 'fred'

_.lowerFirst('FRED');
// => 'fRED'

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lt

Description:
  • Checks if `value` is less than `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than `other`.
Example
_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) lte

Description:
  • Checks if `value` is less than or equal to `other`.
Source:
Since:
  • 3.9.0
See:
Checks if `value` is less than or equal to `other`.
Example
_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) merge

Description:
  • This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Source:
Since:
  • 0.5.0
This method is like `_.assign` except that it recursively merges own and inherited enumerable string keyed properties of source objects into the destination object. Source properties that resolve to `undefined` are skipped if a destination value exists. Array and plain object properties are merged recursively. Other objects and value types are overridden by assignment. Source objects are applied from left to right. Subsequent sources overwrite property assignments of previous sources. **Note:** This method mutates `object`.
Example
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) mergeWith

Description:
  • This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
This method is like `_.merge` except that it accepts `customizer` which is invoked to produce the merged values of the destination and source properties. If `customizer` returns `undefined`, merging is handled by the method instead. The `customizer` is invoked with six arguments: (objValue, srcValue, key, object, source, stack). **Note:** This method mutates `object`.
Example
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return objValue.concat(srcValue);
  }
}

var object = { 'a': [1], 'b': [2] };
var other = { 'a': [3], 'b': [4] };

_.mergeWith(object, other, customizer);
// => { 'a': [1, 3], 'b': [2, 4] }

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) method

Description:
  • Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
Creates a function that invokes the method at `path` of a given object. Any additional arguments are provided to the invoked method.
Example
var objects = [
  { 'a': { 'b': _.constant(2) } },
  { 'a': { 'b': _.constant(1) } }
];

_.map(objects, _.method('a.b'));
// => [2, 1]

_.map(objects, _.method(['a', 'b']));
// => [2, 1]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) methodOf

Description:
  • The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Source:
Since:
  • 3.7.0
The opposite of `_.method`; this method creates a function that invokes the method at a given path of `object`. Any additional arguments are provided to the invoked method.
Example
var array = _.times(3, _.constant),
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.methodOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.methodOf(object));
// => [2, 0]

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) multiply

Description:
  • Multiply two numbers.
Source:
Since:
  • 4.7.0
Multiply two numbers.
Example
_.multiply(6, 4);
// => 24

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) next

Description:
  • Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Source:
Since:
  • 4.0.0
Gets the next value on a wrapped object following the [iterator protocol](https://mdn.io/iteration_protocols#iterator).
Example
var wrapped = _([1, 2]);

wrapped.next();
// => { 'done': false, 'value': 1 }

wrapped.next();
// => { 'done': false, 'value': 2 }

wrapped.next();
// => { 'done': true, 'value': undefined }

(static) now

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) omit

Description:
  • The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Source:
Since:
  • 0.1.0
The opposite of `_.pick`; this method creates an object composed of the own and inherited enumerable property paths of `object` that are not omitted. **Note:** This method is considerably slower than `_.pick`.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) over

Description:
  • Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Source:
Since:
  • 4.0.0
Creates a function that invokes `iteratees` with the arguments it receives and returns their results.
Example
var func = _.over([Math.max, Math.min]);

func(1, 2, 3, 4);
// => [4, 1]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overArgs

Description:
  • Creates a function that invokes `func` with its arguments transformed.
Source:
Since:
  • 4.0.0
Creates a function that invokes `func` with its arguments transformed.
Example
function doubled(n) {
  return n * 2;
}

function square(n) {
  return n * n;
}

var func = _.overArgs(function(x, y) {
  return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overEvery

Description:
  • Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **all** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overEvery([Boolean, isFinite]);

func('1');
// => true

func(null);
// => false

func(NaN);
// => false

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) overSome

Description:
  • Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Source:
Since:
  • 4.0.0
Creates a function that checks if **any** of the `predicates` return truthy when invoked with the arguments it receives. Following shorthands are possible for providing predicates. Pass an `Object` and it will be used as an parameter for `_.matches` to create the predicate. Pass an `Array` of parameters for `_.matchesProperty` and the predicate will be created using them.
Example
var func = _.overSome([Boolean, isFinite]);

func('1');
// => true

func(null);
// => true

func(NaN);
// => false

var matchesFunc = _.overSome([{ 'a': 1 }, { 'a': 2 }])
var matchesPropertyFunc = _.overSome([['a', 1], ['a', 2]])

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partial

Description:
  • Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 0.2.0
Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does **not** alter the `this` binding. The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, _, 'fred');
greetFred('hi');
// => 'hi fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partialRight

Description:
  • This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Source:
Since:
  • 1.0.0
This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives. The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments. **Note:** This method doesn't set the "length" property of partially applied functions.
Example
function greet(greeting, name) {
  return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, 'hello', _);
sayHelloTo('fred');
// => 'hello fred'

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) partition

Description:
  • Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Source:
Since:
  • 3.0.0
Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).
Example
var users = [
  { 'user': 'barney',  'age': 36, 'active': false },
  { 'user': 'fred',    'age': 40, 'active': true },
  { 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(users, function(o) { return o.active; });
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition(users, { 'age': 1, 'active': false });
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(users, ['active', false]);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition(users, 'active');
// => objects for [['fred'], ['barney', 'pebbles']]

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) pick

Description:
  • Creates an object composed of the picked `object` properties.
Source:
Since:
  • 0.1.0
Creates an object composed of the picked `object` properties.
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) plant

Description:
  • Creates a clone of the chain sequence planting `value` as the wrapped value.
Source:
Since:
  • 3.2.0
Creates a clone of the chain sequence planting `value` as the wrapped value.
Example
function square(n) {
  return n * n;
}

var wrapped = _([1, 2]).map(square);
var other = wrapped.plant([3, 4]);

other.value();
// => [9, 16]

wrapped.value();
// => [1, 4]

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pull

Description:
  • Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Source:
Since:
  • 2.0.0
Removes all given values from `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.without`, this method mutates `array`. Use `_.remove` to remove elements from an array by predicate.
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(array, 'a', 'c');
console.log(array);
// => ['b', 'b']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) pullAt

Description:
  • Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Source:
Since:
  • 3.0.0
Removes elements from `array` corresponding to `indexes` and returns an array of removed elements. **Note:** Unlike `_.at`, this method mutates `array`.
Example
var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt(array, [1, 3]);

console.log(array);
// => ['a', 'c']

console.log(pulled);
// => ['b', 'd']

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) range

Description:
  • Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.1.0
See:
  • _.inRange, _.rangeRight
Creates an array of numbers (positive and/or negative) progressing from `start` up to, but not including, `end`. A step of `-1` is used if a negative `start` is specified without an `end` or `step`. If `end` is not specified, it's set to `start` with `start` then set to `0`. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Example
_.range(4);
// => [0, 1, 2, 3]

_.range(-4);
// => [0, -1, -2, -3]

_.range(1, 5);
// => [1, 2, 3, 4]

_.range(0, 20, 5);
// => [0, 5, 10, 15]

_.range(0, -4, -1);
// => [0, -1, -2, -3]

_.range(1, 4, 0);
// => [1, 1, 1]

_.range(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rangeRight

Description:
  • This method is like `_.range` except that it populates values in descending order.
Source:
Since:
  • 4.0.0
See:
  • _.inRange, _.range
This method is like `_.range` except that it populates values in descending order.
Example
_.rangeRight(4);
// => [3, 2, 1, 0]

_.rangeRight(-4);
// => [-3, -2, -1, 0]

_.rangeRight(1, 5);
// => [4, 3, 2, 1]

_.rangeRight(0, 20, 5);
// => [15, 10, 5, 0]

_.rangeRight(0, -4, -1);
// => [-3, -2, -1, 0]

_.rangeRight(1, 4, 0);
// => [1, 1, 1]

_.rangeRight(0);
// => []

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) rearg

Description:
  • Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Source:
Since:
  • 3.0.0
Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.
Example
var rearged = _.rearg(function(a, b, c) {
  return [a, b, c];
}, [2, 0, 1]);

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) reverse

Description:
  • This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Source:
Since:
  • 0.1.0
This method is the wrapper version of `_.reverse`. **Note:** This method mutates the wrapped array.
Example
var array = [1, 2, 3];

_(array).reverse().value()
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) round

Description:
  • Computes `number` rounded to `precision`.
Source:
Since:
  • 3.10.0
Computes `number` rounded to `precision`.
Example
_.round(4.006);
// => 4

_.round(4.006, 2);
// => 4.01

_.round(4060, -2);
// => 4100

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) snakeCase

Description:
  • Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Source:
Since:
  • 3.0.0
Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case).
Example
_.snakeCase('Foo Bar');
// => 'foo_bar'

_.snakeCase('fooBar');
// => 'foo_bar'

_.snakeCase('--FOO-BAR--');
// => 'foo_bar'

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) sortBy

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) startCase

Description:
  • Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Source:
Since:
  • 3.1.0
Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage).
Example
_.startCase('--foo-bar--');
// => 'Foo Bar'

_.startCase('fooBar');
// => 'Foo Bar'

_.startCase('__FOO_BAR__');
// => 'FOO BAR'

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) subtract

Description:
  • Subtract two numbers.
Source:
Since:
  • 4.0.0
Subtract two numbers.
Example
_.subtract(6, 4);
// => 2

(static) templateSettings :Object

Description:
  • By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Source:
By default, the template delimiters used by lodash are like those in embedded Ruby (ERB) as well as ES2015 template strings. Change the following template settings to use alternative delimiters.
Type:
  • Object

(static) toInteger

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3

(static) toNumber

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Converts `value` to a number.
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) union

Description:
  • Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Source:
Since:
  • 0.1.0
Creates an array of unique values, in order, from all given arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons.
Example
_.union([2], [1, 2]);
// => [2, 1]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionBy

Description:
  • This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument: (value).
Example
_.unionBy([2.1], [1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) unionWith

Description:
  • This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(objects, others, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperCase

Description:
  • Converts `string`, as space separated words, to upper case.
Source:
Since:
  • 4.0.0
Converts `string`, as space separated words, to upper case.
Example
_.upperCase('--foo-bar');
// => 'FOO BAR'

_.upperCase('fooBar');
// => 'FOO BAR'

_.upperCase('__foo_bar__');
// => 'FOO BAR'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) upperFirst

Description:
  • Converts the first character of `string` to upper case.
Source:
Since:
  • 4.0.0
Converts the first character of `string` to upper case.
Example
_.upperFirst('fred');
// => 'Fred'

_.upperFirst('FRED');
// => 'FRED'

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) without

Description:
  • Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
  • _.difference, _.xor
Creates an array excluding all given values using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. **Note:** Unlike `_.pull`, this method returns a new array.
Example
_.without([2, 1, 2, 3], 1, 2);
// => [3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xor

Description:
  • Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Source:
Since:
  • 2.4.0
See:
  • _.difference, _.without
Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) of the given arrays. The order of result values is determined by the order they occur in the arrays.
Example
_.xor([2, 1], [2, 3]);
// => [1, 3]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorBy

Description:
  • This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).
Example
_.xorBy([2.1, 1.2], [2.3, 3.4], Math.floor);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 2 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) xorWith

Description:
  • This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(objects, others, _.isEqual);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zip

Description:
  • Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Source:
Since:
  • 0.1.0
Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.
Example
_.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

(static) zipWith

Description:
  • This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Example
_.zipWith([1, 2], [10, 20], [100, 200], function(a, b, c) {
  return a + b + c;
});
// => [111, 222]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

value

Description:
  • Executes the chain sequence to resolve the unwrapped value.
Source:
Since:
  • 0.1.0
Executes the chain sequence to resolve the unwrapped value.
Example
_([1, 2, 3]).value();
// => [1, 2, 3]

Methods

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) after(n, func) → {function}

Description:
  • The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.
Source:
Since:
  • 0.1.0
Example
var saves = ['profile', 'settings'];

var done = _.after(saves.length, function() {
  console.log('done saving!');
});

_.forEach(saves, function(type) {
  asyncSave({ 'type': type, 'complete': done });
});
// => Logs 'done saving!' after the two async saves have completed.
Parameters:
Name Type Description
n number The number of calls before `func` is invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) ary(func, nopt) → {function}

Description:
  • Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.
Source:
Since:
  • 3.0.0
Example
_.map(['6', '8', '10'], _.ary(parseInt, 1));
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
func function The function to cap arguments for.
n number <optional>
func.length The arity cap.
Returns:
Returns the new capped function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) before(n, func) → {function}

Description:
  • Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.
Source:
Since:
  • 3.0.0
Example
jQuery(element).on('click', _.before(5, addContactToList));
// => Allows adding up to 4 contacts to the list.
Parameters:
Name Type Description
n number The number of calls at which `func` is no longer invoked.
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) capitalize(stringopt) → {string}

Description:
  • Converts the first character of `string` to upper case and the remaining to lower case.
Source:
Since:
  • 3.0.0
Example
_.capitalize('FRED');
// => 'Fred'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to capitalize.
Returns:
Returns the capitalized string.
Type
string

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) castArray(value) → {Array}

Description:
  • Casts `value` as an array if it's not one.
Source:
Since:
  • 4.4.0
Example
_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray();
// => []

var array = [1, 2, 3];
console.log(_.castArray(array) === array);
// => true
Parameters:
Name Type Description
value * The value to inspect.
Returns:
Returns the cast array.
Type
Array

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chain(value) → {Object}

Description:
  • Creates a `lodash` wrapper instance that wraps `value` with explicit method chain sequences enabled. The result of such sequences must be unwrapped with `_#value`.
Source:
Since:
  • 1.3.0
Example
var users = [
  { 'user': 'barney',  'age': 36 },
  { 'user': 'fred',    'age': 40 },
  { 'user': 'pebbles', 'age': 1 }
];

var youngest = _
  .chain(users)
  .sortBy('age')
  .map(function(o) {
    return o.user + ' is ' + o.age;
  })
  .head()
  .value();
// => 'pebbles is 1'
Parameters:
Name Type Description
value * The value to wrap.
Returns:
Returns the new `lodash` wrapper instance.
Type
Object

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) chunk(array, sizeopt) → {Array}

Description:
  • Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.
Source:
Since:
  • 3.0.0
Example
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]
Parameters:
Name Type Attributes Default Description
array Array The array to process.
size number <optional>
1 The length of each chunk
Returns:
Returns the new array of chunks.
Type
Array

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clamp(number, loweropt, upper) → {number}

Description:
  • Clamps `number` within the inclusive `lower` and `upper` bounds.
Source:
Since:
  • 4.0.0
Example
_.clamp(-10, -5, 5);
// => -5

_.clamp(10, -5, 5);
// => 5
Parameters:
Name Type Attributes Description
number number The number to clamp.
lower number <optional>
The lower bound.
upper number The upper bound.
Returns:
Returns the clamped number.
Type
number

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) clone(value) → {*}

Description:
  • Creates a shallow clone of `value`. **Note:** This method is loosely based on the [structured clone algorithm](https://mdn.io/Structured_clone_algorithm) and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.
Source:
Since:
  • 0.1.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
console.log(shallow[0] === objects[0]);
// => true
Parameters:
Name Type Description
value * The value to clone.
Returns:
Returns the cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeep(value) → {*}

Description:
  • This method is like `_.clone` except that it recursively clones `value`.
Source:
Since:
  • 1.0.0
See:
Example
var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false
Parameters:
Name Type Description
value * The value to recursively clone.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneDeepWith(value, customizeropt) → {*}

Description:
  • This method is like `_.cloneWith` except that it recursively clones `value`.
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(true);
  }
}

var el = _.cloneDeepWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 20
Parameters:
Name Type Attributes Description
value * The value to recursively clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the deep cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) cloneWith(value, customizeropt) → {*}

Description:
  • This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).
Source:
Since:
  • 4.0.0
See:
Example
function customizer(value) {
  if (_.isElement(value)) {
    return value.cloneNode(false);
  }
}

var el = _.cloneWith(document.body, customizer);

console.log(el === document.body);
// => false
console.log(el.nodeName);
// => 'BODY'
console.log(el.childNodes.length);
// => 0
Parameters:
Name Type Attributes Description
value * The value to clone.
customizer function <optional>
The function to customize cloning.
Returns:
Returns the cloned value.
Type
*

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) compact(array) → {Array}

Description:
  • Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.
Source:
Since:
  • 0.1.0
Example
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
Parameters:
Name Type Description
array Array The array to compact.
Returns:
Returns the new array of filtered values.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) concat(array, …valuesopt) → {Array}

Description:
  • Creates a new array concatenating `array` with any additional arrays and/or values.
Source:
Since:
  • 4.0.0
Example
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);

console.log(other);
// => [1, 2, 3, [4]]

console.log(array);
// => [1]
Parameters:
Name Type Attributes Description
array Array The array to concatenate.
values * <optional>
<repeatable>
The values to concatenate.
Returns:
Returns the new concatenated array.
Type
Array

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) cond(pairs) → {function}

Description:
  • Creates a function that iterates over `pairs` and invokes the corresponding function of the first predicate to return truthy. The predicate-function pairs are invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 4.0.0
Example
var func = _.cond([
  [_.matches({ 'a': 1 }),           _.constant('matches A')],
  [_.conforms({ 'b': _.isNumber }), _.constant('matches B')],
  [_.stubTrue,                      _.constant('no match')]
]);

func({ 'a': 1, 'b': 2 });
// => 'matches A'

func({ 'a': 0, 'b': 1 });
// => 'matches B'

func({ 'a': '1', 'b': '2' });
// => 'no match'
Parameters:
Name Type Description
pairs Array The predicate-function pairs.
Returns:
Returns the new composite function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conforms(source) → {function}

Description:
  • Creates a function that invokes the predicate properties of `source` with the corresponding property values of a given object, returning `true` if all predicates return truthy, else `false`. **Note:** The created function is equivalent to `_.conformsTo` with `source` partially applied.
Source:
Since:
  • 4.0.0
Example
var objects = [
  { 'a': 2, 'b': 1 },
  { 'a': 1, 'b': 2 }
];

_.filter(objects, _.conforms({ 'b': function(n) { return n > 1; } }));
// => [{ 'a': 1, 'b': 2 }]
Parameters:
Name Type Description
source Object The object of property predicates to conform to.
Returns:
Returns the new spec function.
Type
function

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) conformsTo(object, source) → {boolean}

Description:
  • Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`. **Note:** This method is equivalent to `_.conforms` when `source` is partially applied.
Source:
Since:
  • 4.14.0
Example
var object = { 'a': 1, 'b': 2 };

_.conformsTo(object, { 'b': function(n) { return n > 1; } });
// => true

_.conformsTo(object, { 'b': function(n) { return n > 2; } });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property predicates to conform to.
Returns:
Returns `true` if `object` conforms, else `false`.
Type
boolean

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) constant(value) → {function}

Description:
  • Creates a function that returns `value`.
Source:
Since:
  • 2.4.0
Example
var objects = _.times(2, _.constant({ 'a': 1 }));

console.log(objects);
// => [{ 'a': 1 }, { 'a': 1 }]

console.log(objects[0] === objects[1]);
// => true
Parameters:
Name Type Description
value * The value to return from the new function.
Returns:
Returns the new constant function.
Type
function

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) create(prototype, propertiesopt) → {Object}

Description:
  • Creates an object that inherits from the `prototype` object. If a `properties` object is given, its own enumerable string keyed properties are assigned to the created object.
Source:
Since:
  • 2.3.0
Example
function Shape() {
  this.x = 0;
  this.y = 0;
}

function Circle() {
  Shape.call(this);
}

Circle.prototype = _.create(Shape.prototype, {
  'constructor': Circle
});

var circle = new Circle;
circle instanceof Circle;
// => true

circle instanceof Shape;
// => true
Parameters:
Name Type Attributes Description
prototype Object The object to inherit from.
properties Object <optional>
The properties to assign to the object.
Returns:
Returns the new object.
Type
Object

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curry(func, arityopt) → {function}

Description:
  • Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient. The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 2.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) curryRight(func, arityopt) → {function}

Description:
  • This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`. The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments. **Note:** This method doesn't set the "length" property of curried functions.
Source:
Since:
  • 3.0.0
Example
var abc = function(a, b, c) {
  return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
func function The function to curry.
arity number <optional>
func.length The arity of `func`.
Returns:
Returns the new curried function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) debounce(func, waitopt, optionsopt) → {function}

Description:
  • Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.debounce` and `_.throttle`.
Source:
Since:
  • 0.1.0
Example
// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce(sendMail, 300, {
  'leading': true,
  'trailing': false
}));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to debounce.
wait number <optional>
0 The number of milliseconds to delay.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
false Specify invoking on the leading edge of the timeout.
maxWait number <optional>
The maximum time `func` is allowed to be delayed before it's invoked.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new debounced function.
Type
function

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) deburr(stringopt) → {string}

Description:
  • Deburrs `string` by converting [Latin-1 Supplement](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) and [Latin Extended-A](https://en.wikipedia.org/wiki/Latin_Extended-A) letters to basic Latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks).
Source:
Since:
  • 3.0.0
Example
_.deburr('déjà vu');
// => 'deja vu'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to deburr.
Returns:
Returns the deburred string.
Type
string

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) defaultTo(value, defaultValue) → {*}

Description:
  • Checks `value` to determine whether a default value should be returned in its place. The `defaultValue` is returned if `value` is `NaN`, `null`, or `undefined`.
Source:
Since:
  • 4.14.0
Example
_.defaultTo(1, 10);
// => 1

_.defaultTo(undefined, 10);
// => 10
Parameters:
Name Type Description
value * The value to check.
defaultValue * The default value.
Returns:
Returns the resolved value.
Type
*

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) drop(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the beginning.
Source:
Since:
  • 0.5.0
Example
_.drop([1, 2, 3]);
// => [2, 3]

_.drop([1, 2, 3], 2);
// => [3]

_.drop([1, 2, 3], 5);
// => []

_.drop([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements dropped from the end.
Source:
Since:
  • 3.0.0
Example
_.dropRight([1, 2, 3]);
// => [1, 2]

_.dropRight([1, 2, 3], 2);
// => [1]

_.dropRight([1, 2, 3], 5);
// => []

_.dropRight([1, 2, 3], 0);
// => [1, 2, 3]
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to drop.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(users, function(o) { return !o.active; });
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(users, ['active', false]);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) dropWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.dropWhile(users, function(o) { return !o.active; });
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(users, ['active', false]);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile(users, 'active');
// => objects for ['barney', 'fred', 'pebbles']
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) each(collection, iterateeopt) → {Array|Object}

Description:
  • Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`. **Note:** As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.
Source:
Since:
  • 0.1.0
See:
  • _.forEachRight
Example
_.forEach([1, 2], function(value) {
  console.log(value);
});
// => Logs `1` then `2`.

_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) eachRight(collection, iterateeopt) → {Array|Object}

Description:
  • This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
See:
  • _.forEach
Example
_.forEachRight([1, 2], function(value) {
  console.log(value);
});
// => Logs `2` then `1`.
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `collection`.
Type
Array | Object

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) endsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` ends with the given target string.
Source:
Since:
  • 3.0.0
Example
_.endsWith('abc', 'c');
// => true

_.endsWith('abc', 'b');
// => false

_.endsWith('abc', 'b', 2);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
string.length The position to search up to.
Returns:
Returns `true` if `string` ends with `target`, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) eq(value, other) → {boolean}

Description:
  • Performs a [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) comparison between two values to determine if they are equivalent.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escape(stringopt) → {string}

Description:
  • Converts the characters "&", "<", ">", '"', and "'" in `string` to their corresponding HTML entities. **Note:** No other characters are escaped. To escape additional characters use a third-party library like [_he_](https://mths.be/he). Though the ">" character is escaped for symmetry, characters like ">" and "/" don't need escaping in HTML and have no special meaning unless they're part of a tag or unquoted attribute value. See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) (under "semi-related fun fact") for more details. When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) to reduce XSS vectors.
Source:
Since:
  • 0.1.0
Example
_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) escapeRegExp(stringopt) → {string}

Description:
  • Escapes the `RegExp` special characters "^", "$", "\", ".", "*", "+", "?", "(", ")", "[", "]", "{", "}", and "|" in `string`.
Source:
Since:
  • 3.0.0
Example
_.escapeRegExp('[lodash](https://lodash.com/)');
// => '\[lodash\]\(https://lodash\.com/\)'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to escape.
Returns:
Returns the escaped string.
Type
string

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) every(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **all** elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** This method returns `true` for [empty collections](https://en.wikipedia.org/wiki/Empty_set) because [everything is true](https://en.wikipedia.org/wiki/Vacuous_truth) of elements of empty collections.
Source:
Since:
  • 0.1.0
Example
_.every([true, 1, null, 'yes'], Boolean);
// => false

var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.every(users, 'active');
// => false
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if all elements pass the predicate check, else `false`.
Type
boolean

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) fill(array, value, startopt, endopt) → {Array}

Description:
  • Fills elements of `array` with `value` from `start` up to, but not including, `end`. **Note:** This method mutates `array`.
Source:
Since:
  • 3.2.0
Example
var array = [1, 2, 3];

_.fill(array, 'a');
console.log(array);
// => ['a', 'a', 'a']

_.fill(Array(3), 2);
// => [2, 2, 2]

_.fill([4, 6, 8, 10], '*', 1, 3);
// => [4, '*', '*', 10]
Parameters:
Name Type Attributes Default Description
array Array The array to fill.
value * The value to fill `array` with.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns `array`.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) filter(collection, predicateopt) → {Array}

Description:
  • Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection). **Note:** Unlike `_.remove`, this method returns a new array.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(users, _.overSome([{ 'age': 36 }, ['age', 40]]));
// => objects for ['fred', 'barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.findIndex(users, function(o) { return o.user == 'barney'; });
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex(users, { 'user': 'fred', 'active': false });
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(users, ['active', false]);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex(users, 'active');
// => 2
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.find` except that it returns the key of the first element `predicate` returns truthy for instead of the element itself.
Source:
Since:
  • 1.1.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(users, function(o) { return o.age < 40; });
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey(users, 'active');
// => 'barney'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastIndex(array, predicateopt, fromIndexopt) → {number}

Description:
  • This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 2.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the found element, else `-1`.
Type
number

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) findLastKey(object, predicateopt) → {string|undefined}

Description:
  • This method is like `_.findKey` except that it iterates over elements of a collection in the opposite order.
Source:
Since:
  • 2.0.0
Example
var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findLastKey(users, function(o) { return o.age < 40; });
// => returns 'pebbles' assuming `_.findKey` returns 'barney'

// The `_.matches` iteratee shorthand.
_.findLastKey(users, { 'age': 36, 'active': true });
// => 'barney'

// The `_.matchesProperty` iteratee shorthand.
_.findLastKey(users, ['active', false]);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findLastKey(users, 'active');
// => 'pebbles'
Parameters:
Name Type Attributes Default Description
object Object The object to inspect.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the key of the matched element, else `undefined`.
Type
string | undefined

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) first(array) → {*}

Description:
  • Gets the first element of `array`.
Source:
Since:
  • 0.1.0
Example
_.head([1, 2, 3]);
// => 1

_.head([]);
// => undefined
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the first element of `array`.
Type
*

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMap(collection, iterateeopt) → {Array}

Description:
  • Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 4.0.0
Example
function duplicate(n) {
  return [n, n];
}

_.flatMap([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDeep(collection, iterateeopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDeep([1, 2], duplicate);
// => [1, 1, 2, 2]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatMapDepth(collection, iterateeopt, depthopt) → {Array}

Description:
  • This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.
Source:
Since:
  • 4.7.0
Example
function duplicate(n) {
  return [[[n, n]]];
}

_.flatMapDepth([1, 2], duplicate, 2);
// => [[1, 1], [2, 2]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flatten(array) → {Array}

Description:
  • Flattens `array` a single level deep.
Source:
Since:
  • 0.1.0
Example
_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDeep(array) → {Array}

Description:
  • Recursively flattens `array`.
Source:
Since:
  • 3.0.0
Example
_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]
Parameters:
Name Type Description
array Array The array to flatten.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flattenDepth(array, depthopt) → {Array}

Description:
  • Recursively flatten `array` up to `depth` times.
Source:
Since:
  • 4.4.0
Example
var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(array, 1);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(array, 2);
// => [1, 2, 3, [4], 5]
Parameters:
Name Type Attributes Default Description
array Array The array to flatten.
depth number <optional>
1 The maximum recursion depth.
Returns:
Returns the new flattened array.
Type
Array

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) flip(func) → {function}

Description:
  • Creates a function that invokes `func` with arguments reversed.
Source:
Since:
  • 4.0.0
Example
var flipped = _.flip(function() {
  return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']
Parameters:
Name Type Description
func function The function to flip arguments for.
Returns:
Returns the new flipped function.
Type
function

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forIn(object, iterateeopt) → {Object}

Description:
  • Iterates over own and inherited enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forIn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a', 'b', then 'c' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forInRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forIn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forInRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'c', 'b', then 'a' assuming `_.forIn` logs 'a', 'b', then 'c'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwn(object, iterateeopt) → {Object}

Description:
  • Iterates over own enumerable string keyed properties of an object and invokes `iteratee` for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 0.3.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwn(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) forOwnRight(object, iterateeopt) → {Object}

Description:
  • This method is like `_.forOwn` except that it iterates over properties of `object` in the opposite order.
Source:
Since:
  • 2.0.0
See:
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.forOwnRight(new Foo, function(value, key) {
  console.log(key);
});
// => Logs 'b' then 'a' assuming `_.forOwn` logs 'a' then 'b'.
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `object`.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) fromPairs(pairs) → {Object}

Description:
  • The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.
Source:
Since:
  • 4.0.0
Example
_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Description
pairs Array The key-value pairs.
Returns:
Returns the new object.
Type
Object

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functions(object) → {Array}

Description:
  • Creates an array of function property names from own enumerable properties of `object`.
Source:
Since:
  • 0.1.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functions(new Foo);
// => ['a', 'b']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) functionsIn(object) → {Array}

Description:
  • Creates an array of function property names from own and inherited enumerable properties of `object`.
Source:
Since:
  • 4.0.0
See:
Example
function Foo() {
  this.a = _.constant('a');
  this.b = _.constant('b');
}

Foo.prototype.c = _.constant('c');

_.functionsIn(new Foo);
// => ['a', 'b', 'c']
Parameters:
Name Type Description
object Object The object to inspect.
Returns:
Returns the function names.
Type
Array

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) get(object, path, defaultValueopt) → {*}

Description:
  • Gets the value at `path` of `object`. If the resolved value is `undefined`, the `defaultValue` is returned in its place.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to get.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) has(object, path) → {boolean}

Description:
  • Checks if `path` is a direct property of `object`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': { 'b': 2 } };
var other = _.create({ 'a': _.create({ 'b': 2 }) });

_.has(object, 'a');
// => true

_.has(object, 'a.b');
// => true

_.has(object, ['a', 'b']);
// => true

_.has(other, 'a');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) hasIn(object, path) → {boolean}

Description:
  • Checks if `path` is a direct or inherited property of `object`.
Source:
Since:
  • 4.0.0
Example
var object = _.create({ 'a': _.create({ 'b': 2 }) });

_.hasIn(object, 'a');
// => true

_.hasIn(object, 'a.b');
// => true

_.hasIn(object, ['a', 'b']);
// => true

_.hasIn(object, 'b');
// => false
Parameters:
Name Type Description
object Object The object to query.
path Array | string The path to check.
Returns:
Returns `true` if `path` exists, else `false`.
Type
boolean

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) identity(value) → {*}

Description:
  • This method returns the first argument it receives.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };

console.log(_.identity(object) === object);
// => true
Parameters:
Name Type Description
value * Any value.
Returns:
Returns `value`.
Type
*

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) inRange(number, startopt, end) → {boolean}

Description:
  • Checks if `n` is between `start` and up to, but not including, `end`. If `end` is not specified, it's set to `start` with `start` then set to `0`. If `start` is greater than `end` the params are swapped to support negative ranges.
Source:
Since:
  • 3.3.0
See:
  • _.range, _.rangeRight
Example
_.inRange(3, 2, 4);
// => true

_.inRange(4, 8);
// => true

_.inRange(4, 2);
// => false

_.inRange(2, 2);
// => false

_.inRange(1.2, 2);
// => true

_.inRange(5.2, 4);
// => false

_.inRange(-3, -2, -6);
// => true
Parameters:
Name Type Attributes Default Description
number number The number to check.
start number <optional>
0 The start of the range.
end number The end of the range.
Returns:
Returns `true` if `number` is in the range, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) includes(collection, value, fromIndexopt) → {boolean}

Description:
  • Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.
Source:
Since:
  • 0.1.0
Example
_.includes([1, 2, 3], 1);
// => true

_.includes([1, 2, 3], 1, 2);
// => false

_.includes({ 'a': 1, 'b': 2 }, 1);
// => true

_.includes('abcd', 'bc');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object | string The collection to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns `true` if `value` is found, else `false`.
Type
boolean

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) indexOf(array, value, fromIndexopt) → {number}

Description:
  • Gets the index at which the first occurrence of `value` is found in `array` using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.
Source:
Since:
  • 0.1.0
Example
_.indexOf([1, 2, 1, 2], 2);
// => 1

// Search from the `fromIndex`.
_.indexOf([1, 2, 1, 2], 2, 2);
// => 3
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
0 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) initial(array) → {Array}

Description:
  • Gets all but the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.initial([1, 2, 3]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLike(value) → {boolean}

Description:
  • Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
Source:
Since:
  • 4.0.0
Example
_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is array-like, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isArrayLikeObject(value) → {boolean}

Description:
  • This method is like `_.isArrayLike` except that it also checks if `value` is an object.
Source:
Since:
  • 4.0.0
Example
_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an array-like object, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isBoolean(value) → {boolean}

Description:
  • Checks if `value` is classified as a boolean primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isBoolean(false);
// => true

_.isBoolean(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a boolean, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isElement(value) → {boolean}

Description:
  • Checks if `value` is likely a DOM element.
Source:
Since:
  • 0.1.0
Example
_.isElement(document.body);
// => true

_.isElement('<body>');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a DOM element, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEmpty(value) → {boolean}

Description:
  • Checks if `value` is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties. Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.
Source:
Since:
  • 0.1.0
Example
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is empty, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqual(value, other) → {boolean}

Description:
  • Performs a deep comparison between two values to determine if they are equivalent. **Note:** This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false
Parameters:
Name Type Description
value * The value to compare.
other * The other value to compare.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isEqualWith(value, other, customizeropt) → {boolean}

Description:
  • This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, othValue) {
  if (isGreeting(objValue) && isGreeting(othValue)) {
    return true;
  }
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(array, other, customizer);
// => true
Parameters:
Name Type Attributes Description
value * The value to compare.
other * The other value to compare.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if the values are equivalent, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isError(value) → {boolean}

Description:
  • Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.
Source:
Since:
  • 3.0.0
Example
_.isError(new Error);
// => true

_.isError(Error);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an error object, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFinite(value) → {boolean}

Description:
  • Checks if `value` is a finite primitive number. **Note:** This method is based on [`Number.isFinite`](https://mdn.io/Number/isFinite).
Source:
Since:
  • 0.1.0
Example
_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a finite number, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isFunction(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Function` object.
Source:
Since:
  • 0.1.0
Example
_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a function, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isInteger(value) → {boolean}

Description:
  • Checks if `value` is an integer. **Note:** This method is based on [`Number.isInteger`](https://mdn.io/Number/isInteger).
Source:
Since:
  • 4.0.0
Example
_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an integer, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isLength(value) → {boolean}

Description:
  • Checks if `value` is a valid array-like length. **Note:** This method is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a valid length, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatch(object, source) → {boolean}

Description:
  • Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values. **Note:** This method is equivalent to `_.matches` when `source` is partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.
Source:
Since:
  • 3.0.0
Example
var object = { 'a': 1, 'b': 2 };

_.isMatch(object, { 'b': 2 });
// => true

_.isMatch(object, { 'b': 1 });
// => false
Parameters:
Name Type Description
object Object The object to inspect.
source Object The object of property values to match.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isMatchWith(object, source, customizeropt) → {boolean}

Description:
  • This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).
Source:
Since:
  • 4.0.0
Example
function isGreeting(value) {
  return /^h(?:i|ello)$/.test(value);
}

function customizer(objValue, srcValue) {
  if (isGreeting(objValue) && isGreeting(srcValue)) {
    return true;
  }
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(object, source, customizer);
// => true
Parameters:
Name Type Attributes Description
object Object The object to inspect.
source Object The object of property values to match.
customizer function <optional>
The function to customize comparisons.
Returns:
Returns `true` if `object` is a match, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNaN(value) → {boolean}

Description:
  • Checks if `value` is `NaN`. **Note:** This method is based on [`Number.isNaN`](https://mdn.io/Number/isNaN) and is not the same as global [`isNaN`](https://mdn.io/isNaN) which returns `true` for `undefined` and other non-number values.
Source:
Since:
  • 0.1.0
Example
_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `NaN`, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNative(value) → {boolean}

Description:
  • Checks if `value` is a pristine native function. **Note:** This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill), which rely on core-js.
Source:
Since:
  • 3.0.0
Example
_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a native function, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNil(value) → {boolean}

Description:
  • Checks if `value` is `null` or `undefined`.
Source:
Since:
  • 4.0.0
Example
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is nullish, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNull(value) → {boolean}

Description:
  • Checks if `value` is `null`.
Source:
Since:
  • 0.1.0
Example
_.isNull(null);
// => true

_.isNull(void 0);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `null`, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isNumber(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Number` primitive or object. **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.
Source:
Since:
  • 0.1.0
Example
_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a number, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObject(value) → {boolean}

Description:
  • Checks if `value` is the [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types) of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
Source:
Since:
  • 0.1.0
Example
_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is an object, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isObjectLike(value) → {boolean}

Description:
  • Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".
Source:
Since:
  • 4.0.0
Example
_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is object-like, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isPlainObject(value) → {boolean}

Description:
  • Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.
Source:
Since:
  • 0.8.0
Example
function Foo() {
  this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a plain object, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isSafeInteger(value) → {boolean}

Description:
  • Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer. **Note:** This method is based on [`Number.isSafeInteger`](https://mdn.io/Number/isSafeInteger).
Source:
Since:
  • 4.0.0
Example
_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a safe integer, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isString(value) → {boolean}

Description:
  • Checks if `value` is classified as a `String` primitive or object.
Source:
Since:
  • 0.1.0
Example
_.isString('abc');
// => true

_.isString(1);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a string, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isSymbol(value) → {boolean}

Description:
  • Checks if `value` is classified as a `Symbol` primitive or object.
Source:
Since:
  • 4.0.0
Example
_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a symbol, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isUndefined(value) → {boolean}

Description:
  • Checks if `value` is `undefined`.
Source:
Since:
  • 0.1.0
Example
_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is `undefined`, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakMap(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakMap` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak map, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) isWeakSet(value) → {boolean}

Description:
  • Checks if `value` is classified as a `WeakSet` object.
Source:
Since:
  • 4.3.0
Example
_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false
Parameters:
Name Type Description
value * The value to check.
Returns:
Returns `true` if `value` is a weak set, else `false`.
Type
boolean

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) iteratee(funcopt) → {function}

Description:
  • Creates a function that invokes `func` with the arguments of the created function. If `func` is a property name, the created function returns the property value for a given element. If `func` is an array or object, the created function returns `true` for elements that contain the equivalent source properties, otherwise it returns `false`.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.filter(users, _.iteratee({ 'user': 'barney', 'active': true }));
// => [{ 'user': 'barney', 'age': 36, 'active': true }]

// The `_.matchesProperty` iteratee shorthand.
_.filter(users, _.iteratee(['user', 'fred']));
// => [{ 'user': 'fred', 'age': 40 }]

// The `_.property` iteratee shorthand.
_.map(users, _.iteratee('user'));
// => ['barney', 'fred']

// Create custom iteratee shorthands.
_.iteratee = _.wrap(_.iteratee, function(iteratee, func) {
  return !_.isRegExp(func) ? iteratee(func) : function(string) {
    return func.test(string);
  };
});

_.filter(['abc', 'def'], /ef/);
// => ['def']
Parameters:
Name Type Attributes Default Description
func * <optional>
_.identity The value to convert to a callback.
Returns:
Returns the callback.
Type
function

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) join(array, separatoropt) → {string}

Description:
  • Converts all elements in `array` into a string separated by `separator`.
Source:
Since:
  • 4.0.0
Example
_.join(['a', 'b', 'c'], '~');
// => 'a~b~c'
Parameters:
Name Type Attributes Default Description
array Array The array to convert.
separator string <optional>
',' The element separator.
Returns:
Returns the joined string.
Type
string

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keys(object) → {Array}

Description:
  • Creates an array of the own enumerable property names of `object`. **Note:** Non-object values are coerced to objects. See the [ES spec](http://ecma-international.org/ecma-262/7.0/#sec-object.keys) for more details.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keys(new Foo);
// => ['a', 'b'] (iteration order is not guaranteed)

_.keys('hi');
// => ['0', '1']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) keysIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable property names of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.keysIn(new Foo);
// => ['a', 'b', 'c'] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property names.
Type
Array

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) last(array) → {*}

Description:
  • Gets the last element of `array`.
Source:
Since:
  • 0.1.0
Example
_.last([1, 2, 3]);
// => 3
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the last element of `array`.
Type
*

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) lastIndexOf(array, value, fromIndexopt) → {number}

Description:
  • This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.
Source:
Since:
  • 0.1.0
Example
_.lastIndexOf([1, 2, 1, 2], 2);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([1, 2, 1, 2], 2, 2);
// => 1
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
value * The value to search for.
fromIndex number <optional>
array.length-1 The index to search from.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) map(collection, iterateeopt) → {Array}

Description:
  • Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments: (value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. The guarded methods are: `ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`
Source:
Since:
  • 0.1.0
Example
function square(n) {
  return n * n;
}

_.map([4, 8], square);
// => [16, 64]

_.map({ 'a': 4, 'b': 8 }, square);
// => [16, 64] (iteration order is not guaranteed)

var users = [
  { 'user': 'barney' },
  { 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map(users, 'user');
// => ['barney', 'fred']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped array.
Type
Array

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapKeys(object, iterateeopt) → {Object}

Description:
  • The opposite of `_.mapValues`; this method creates an object with the same values as `object` and keys generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 3.8.0
See:
Example
_.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
  return key + value;
});
// => { 'a1': 1, 'b2': 2 }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) mapValues(object, iterateeopt) → {Object}

Description:
  • Creates an object with the same keys as `object` and values generated by running each own enumerable string keyed property of `object` thru `iteratee`. The iteratee is invoked with three arguments: (value, key, object).
Source:
Since:
  • 2.4.0
See:
Example
var users = {
  'fred':    { 'user': 'fred',    'age': 40 },
  'pebbles': { 'user': 'pebbles', 'age': 1 }
};

_.mapValues(users, function(o) { return o.age; });
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)

// The `_.property` iteratee shorthand.
_.mapValues(users, 'age');
// => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new mapped object.
Type
Object

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matches(source) → {function}

Description:
  • Creates a function that performs a partial deep comparison between a given object and `source`, returning `true` if the given object has equivalent property values, else `false`. **Note:** The created function is equivalent to `_.isMatch` with `source` partially applied. Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.0.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.filter(objects, _.matches({ 'a': 4, 'c': 6 }));
// => [{ 'a': 4, 'b': 5, 'c': 6 }]

// Checking for several possible values
_.filter(objects, _.overSome([_.matches({ 'a': 1 }), _.matches({ 'a': 4 })]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
source Object The object of property values to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) matchesProperty(path, srcValue) → {function}

Description:
  • Creates a function that performs a partial deep comparison between the value at `path` of a given object to `srcValue`, returning `true` if the object value is equivalent, else `false`. **Note:** Partial comparisons will match empty array and empty object `srcValue` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons. **Note:** Multiple values can be checked by combining several matchers using `_.overSome`
Source:
Since:
  • 3.2.0
Example
var objects = [
  { 'a': 1, 'b': 2, 'c': 3 },
  { 'a': 4, 'b': 5, 'c': 6 }
];

_.find(objects, _.matchesProperty('a', 4));
// => { 'a': 4, 'b': 5, 'c': 6 }

// Checking for several possible values
_.filter(objects, _.overSome([_.matchesProperty('a', 1), _.matchesProperty('a', 4)]));
// => [{ 'a': 1, 'b': 2, 'c': 3 }, { 'a': 4, 'b': 5, 'c': 6 }]
Parameters:
Name Type Description
path Array | string The path of the property to get.
srcValue * The value to match.
Returns:
Returns the new spec function.
Type
function

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) max(array) → {*}

Description:
  • Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) maxBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(objects, function(o) { return o.n; });
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy(objects, 'n');
// => { 'n': 2 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the maximum value.
Type
*

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) mean(array) → {number}

Description:
  • Computes the mean of the values in `array`.
Source:
Since:
  • 4.0.0
Example
_.mean([4, 2, 8, 6]);
// => 5
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) meanBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.7.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(objects, function(o) { return o.n; });
// => 5

// The `_.property` iteratee shorthand.
_.meanBy(objects, 'n');
// => 5
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the mean.
Type
number

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) memoize(func, resolveropt) → {function}

Description:
  • Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function. **Note:** The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object) method interface of `clear`, `delete`, `get`, `has`, and `set`.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;
Parameters:
Name Type Attributes Description
func function The function to have its output memoized.
resolver function <optional>
The function to resolve the cache key.
Returns:
Returns the new memoized function.
Type
function

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) min(array) → {*}

Description:
  • Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.
Source:
Since:
  • 0.1.0
Example
_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) minBy(array, iterateeopt) → {*}

Description:
  • This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(objects, function(o) { return o.n; });
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy(objects, 'n');
// => { 'n': 1 }
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the minimum value.
Type
*

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) mixin(objectopt, source, optionsopt) → {function|Object}

Description:
  • Adds all own enumerable string keyed function properties of a source object to the destination object. If `object` is a function, then methods are added to its prototype as well. **Note:** Use `_.runInContext` to create a pristine `lodash` function to avoid conflicts caused by modifying the original.
Source:
Since:
  • 0.1.0
Example
function vowels(string) {
  return _.filter(string, function(v) {
    return /[aeiou]/i.test(v);
  });
}

_.mixin({ 'vowels': vowels });
_.vowels('fred');
// => ['e']

_('fred').vowels().value();
// => ['e']

_.mixin({ 'vowels': vowels }, { 'chain': false });
_('fred').vowels();
// => ['e']
Parameters:
Name Type Attributes Default Description
object function | Object <optional>
lodash The destination object.
source Object The object of functions to add.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
chain boolean <optional>
true Specify whether mixins are chainable.
Returns:
Returns `object`.
Type
function | Object

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) negate(predicate) → {function}

Description:
  • Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 3.0.0
Example
function isEven(n) {
  return n % 2 == 0;
}

_.filter([1, 2, 3, 4, 5, 6], _.negate(isEven));
// => [1, 3, 5]
Parameters:
Name Type Description
predicate function The predicate to negate.
Returns:
Returns the new negated function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noConflict() → {function}

Description:
  • Reverts the `_` variable to its previous value and returns a reference to the `lodash` function.
Source:
Since:
  • 0.1.0
Example
var lodash = _.noConflict();
Returns:
Returns the `lodash` function.
Type
function

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) noop()

Description:
  • This method returns `undefined`.
Source:
Since:
  • 2.3.0
Example
_.times(2, _.noop);
// => [undefined, undefined]

(static) now() → {number}

Description:
  • Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January 1970 00:00:00 UTC).
Source:
Since:
  • 2.4.0
Example
_.defer(function(stamp) {
  console.log(_.now() - stamp);
}, _.now());
// => Logs the number of milliseconds it took for the deferred invocation.
Returns:
Returns the timestamp.
Type
number

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nth(array, nopt) → {*}

Description:
  • Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.
Source:
Since:
  • 4.11.0
Example
var array = ['a', 'b', 'c', 'd'];

_.nth(array, 1);
// => 'b'

_.nth(array, -2);
// => 'c';
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
0 The index of the element to return.
Returns:
Returns the nth element of `array`.
Type
*

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) nthArg(nopt) → {function}

Description:
  • Creates a function that gets the argument at index `n`. If `n` is negative, the nth argument from the end is returned.
Source:
Since:
  • 4.0.0
Example
var func = _.nthArg(1);
func('a', 'b', 'c', 'd');
// => 'b'

var func = _.nthArg(-2);
func('a', 'b', 'c', 'd');
// => 'c'
Parameters:
Name Type Attributes Default Description
n number <optional>
0 The index of the argument to return.
Returns:
Returns the new pass-thru function.
Type
function

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) omitBy(object, predicateopt) → {Object}

Description:
  • The opposite of `_.pickBy`; this method creates an object composed of the own and inherited enumerable string keyed properties of `object` that `predicate` doesn't return truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omitBy(object, _.isNumber);
// => { 'b': '2' }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) once(func) → {function}

Description:
  • Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.
Source:
Since:
  • 0.1.0
Example
var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once
Parameters:
Name Type Description
func function The function to restrict.
Returns:
Returns the new restricted function.
Type
function

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) orderBy(collection, iterateesopt, ordersopt) → {Array}

Description:
  • This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.
Source:
Since:
  • 4.0.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees Array:.<Array:> | Array:.<function()> | Array:.<Object:> | Array:.<string:> <optional>
[_.identity] The iteratees to sort by.
orders Array:.<string:> <optional>
The sort orders of `iteratees`.
Returns:
Returns the new sorted array.
Type
Array

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) pad(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left and right sides if it's shorter than `length`. Padding characters are truncated if they can't be evenly divided by `length`.
Source:
Since:
  • 3.0.0
Example
_.pad('abc', 8);
// => '  abc   '

_.pad('abc', 8, '_-');
// => '_-abc_-_'

_.pad('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padEnd(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the right side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padEnd('abc', 6);
// => 'abc   '

_.padEnd('abc', 6, '_-');
// => 'abc_-_'

_.padEnd('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) padStart(stringopt, lengthopt, charsopt) → {string}

Description:
  • Pads `string` on the left side if it's shorter than `length`. Padding characters are truncated if they exceed `length`.
Source:
Since:
  • 4.0.0
Example
_.padStart('abc', 6);
// => '   abc'

_.padStart('abc', 6, '_-');
// => '_-_abc'

_.padStart('abc', 3);
// => 'abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to pad.
length number <optional>
0 The padding length.
chars string <optional>
' ' The string used as padding.
Returns:
Returns the padded string.
Type
string

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) parseInt(string, radixopt) → {number}

Description:
  • Converts `string` to an integer of the specified radix. If `radix` is `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, in which case a `radix` of `16` is used. **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#x15.1.2.2) of `parseInt`.
Source:
Since:
  • 1.1.0
Example
_.parseInt('08');
// => 8

_.map(['6', '08', '10'], _.parseInt);
// => [6, 8, 10]
Parameters:
Name Type Attributes Default Description
string string The string to convert.
radix number <optional>
10 The radix to interpret `value` by.
Returns:
Returns the converted integer.
Type
number

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) pickBy(object, predicateopt) → {Object}

Description:
  • Creates an object composed of the `object` properties `predicate` returns truthy for. The predicate is invoked with two arguments: (value, key).
Source:
Since:
  • 4.0.0
Example
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
Parameters:
Name Type Attributes Default Description
object Object The source object.
predicate function <optional>
_.identity The function invoked per property.
Returns:
Returns the new object.
Type
Object

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) property(path) → {function}

Description:
  • Creates a function that returns the value at `path` of a given object.
Source:
Since:
  • 2.4.0
Example
var objects = [
  { 'a': { 'b': 2 } },
  { 'a': { 'b': 1 } }
];

_.map(objects, _.property('a.b'));
// => [2, 1]

_.map(_.sortBy(objects, _.property(['a', 'b'])), 'a.b');
// => [1, 2]
Parameters:
Name Type Description
path Array | string The path of the property to get.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) propertyOf(object) → {function}

Description:
  • The opposite of `_.property`; this method creates a function that returns the value at a given path of `object`.
Source:
Since:
  • 3.0.0
Example
var array = [0, 1, 2],
    object = { 'a': array, 'b': array, 'c': array };

_.map(['a[2]', 'c[0]'], _.propertyOf(object));
// => [2, 0]

_.map([['a', '2'], ['c', '0']], _.propertyOf(object));
// => [2, 0]
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the new accessor function.
Type
function

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAll(array, values) → {Array}

Description:
  • This method is like `_.pull` except that it accepts an array of values to remove. **Note:** Unlike `_.difference`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(array, ['a', 'c']);
console.log(array);
// => ['b', 'b']
Parameters:
Name Type Description
array Array The array to modify.
values Array The values to remove.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllBy(array, values, iterateeopt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value). **Note:** Unlike `_.differenceBy`, this method mutates `array`.
Source:
Since:
  • 4.0.0
Example
var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy(array, [{ 'x': 1 }, { 'x': 3 }], 'x');
console.log(array);
// => [{ 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
values Array The values to remove.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) pullAllWith(array, values, comparatoropt) → {Array}

Description:
  • This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal). **Note:** Unlike `_.differenceWith`, this method mutates `array`.
Source:
Since:
  • 4.6.0
Example
var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
console.log(array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
Parameters:
Name Type Attributes Description
array Array The array to modify.
values Array The values to remove.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns `array`.
Type
Array

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) random(loweropt, upperopt, floatingopt) → {number}

Description:
  • Produces a random number between the inclusive `lower` and `upper` bounds. If only one argument is provided a number between `0` and the given number is returned. If `floating` is `true`, or either `lower` or `upper` are floats, a floating-point number is returned instead of an integer. **Note:** JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
Source:
Since:
  • 0.7.0
Example
_.random(0, 5);
// => an integer between 0 and 5

_.random(5);
// => also an integer between 0 and 5

_.random(5, true);
// => a floating-point number between 0 and 5

_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
Parameters:
Name Type Attributes Default Description
lower number <optional>
0 The lower bound.
upper number <optional>
1 The upper bound.
floating boolean <optional>
Specify returning a floating-point number.
Returns:
Returns the random number.
Type
number

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduce(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments: (accumulator, value, index|key, collection). Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`. The guarded methods are: `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`
Source:
Since:
  • 0.1.0
See:
Example
_.reduce([1, 2], function(sum, n) {
  return sum + n;
}, 0);
// => 3

_.reduce({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
  return result;
}, {});
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reduceRight(collection, iterateeopt, accumulatoropt) → {*}

Description:
  • This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.
Source:
Since:
  • 0.1.0
See:
Example
var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(array, function(flattened, other) {
  return flattened.concat(other);
}, []);
// => [4, 5, 2, 3, 0, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The initial value.
Returns:
Returns the accumulated value.
Type
*

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) reject(collection, predicateopt) → {Array}

Description:
  • The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does **not** return truthy for.
Source:
Since:
  • 0.1.0
See:
Example
var users = [
  { 'user': 'barney', 'age': 36, 'active': false },
  { 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(users, function(o) { return !o.active; });
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject(users, { 'age': 40, 'active': true });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(users, ['active', false]);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject(users, 'active');
// => objects for ['barney']
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new filtered array.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) remove(array, predicateopt) → {Array}

Description:
  • Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array). **Note:** Unlike `_.filter`, this method mutates `array`. Use `_.pull` to pull elements from an array by value.
Source:
Since:
  • 2.0.0
Example
var array = [1, 2, 3, 4];
var evens = _.remove(array, function(n) {
  return n % 2 == 0;
});

console.log(array);
// => [1, 3]

console.log(evens);
// => [2, 4]
Parameters:
Name Type Attributes Default Description
array Array The array to modify.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the new array of removed elements.
Type
Array

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) repeat(stringopt, nopt) → {string}

Description:
  • Repeats the given string `n` times.
Source:
Since:
  • 3.0.0
Example
_.repeat('*', 3);
// => '***'

_.repeat('abc', 2);
// => 'abcabc'

_.repeat('abc', 0);
// => ''
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to repeat.
n number <optional>
1 The number of times to repeat the string.
Returns:
Returns the repeated string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) replace(stringopt, pattern, replacement) → {string}

Description:
  • Replaces matches for `pattern` in `string` with `replacement`. **Note:** This method is based on [`String#replace`](https://mdn.io/String/replace).
Source:
Since:
  • 4.0.0
Example
_.replace('Hi Fred', 'Fred', 'Barney');
// => 'Hi Barney'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to modify.
pattern RegExp | string The pattern to replace.
replacement function | string The match replacement.
Returns:
Returns the modified string.
Type
string

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) rest(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array. **Note:** This method is based on the [rest parameter](https://mdn.io/rest_parameters).
Source:
Since:
  • 4.0.0
Example
var say = _.rest(function(what, names) {
  return what + ' ' + _.initial(names).join(', ') +
    (_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
func function The function to apply a rest parameter to.
start number <optional>
func.length-1 The start position of the rest parameter.
Returns:
Returns the new function.
Type
function

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) result(object, path, defaultValueopt) → {*}

Description:
  • This method is like `_.get` except that if the resolved value is a function it's invoked with the `this` binding of its parent object and its result is returned.
Source:
Since:
  • 0.1.0
Example
var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] };

_.result(object, 'a[0].b.c1');
// => 3

_.result(object, 'a[0].b.c2');
// => 4

_.result(object, 'a[0].b.c3', 'default');
// => 'default'

_.result(object, 'a[0].b.c3', _.constant('default'));
// => 'default'
Parameters:
Name Type Attributes Description
object Object The object to query.
path Array | string The path of the property to resolve.
defaultValue * <optional>
The value returned for `undefined` resolved values.
Returns:
Returns the resolved value.
Type
*

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) reverse(array) → {Array}

Description:
  • Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on. **Note:** This method mutates `array` and is based on [`Array#reverse`](https://mdn.io/Array/reverse).
Source:
Since:
  • 4.0.0
Example
var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

console.log(array);
// => [3, 2, 1]
Parameters:
Name Type Description
array Array The array to modify.
Returns:
Returns `array`.
Type
Array

(static) runInContext(contextopt) → {function}

Description:
  • Create a new pristine `lodash` function using the `context` object.
Source:
Since:
  • 1.1.0
Example
_.mixin({ 'foo': _.constant('foo') });

var lodash = _.runInContext();
lodash.mixin({ 'bar': lodash.constant('bar') });

_.isFunction(_.foo);
// => true
_.isFunction(_.bar);
// => false

lodash.isFunction(lodash.foo);
// => false
lodash.isFunction(lodash.bar);
// => true

// Create a suped-up `defer` in Node.js.
var defer = _.runInContext({ 'setTimeout': setImmediate }).defer;
Parameters:
Name Type Attributes Default Description
context Object <optional>
root The context object.
Returns:
Returns a new `lodash` function.
Type
function

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sample(collection) → {*}

Description:
  • Gets a random element from `collection`.
Source:
Since:
  • 2.0.0
Example
_.sample([1, 2, 3, 4]);
// => 2
Parameters:
Name Type Description
collection Array | Object The collection to sample.
Returns:
Returns the random element.
Type
*

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) sampleSize(collection, nopt) → {Array}

Description:
  • Gets `n` random elements at unique keys from `collection` up to the size of `collection`.
Source:
Since:
  • 4.0.0
Example
_.sampleSize([1, 2, 3], 2);
// => [3, 1]

_.sampleSize([1, 2, 3], 4);
// => [2, 3, 1]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to sample.
n number <optional>
1 The number of elements to sample.
Returns:
Returns the random elements.
Type
Array

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) set(object, path, value) → {Object}

Description:
  • Sets the value at `path` of `object`. If a portion of `path` doesn't exist, it's created. Arrays are created for missing index properties while objects are created for all other missing properties. Use `_.setWith` to customize `path` creation. **Note:** This method mutates `object`.
Source:
Since:
  • 3.7.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) setWith(object, path, value, customizeropt) → {Object}

Description:
  • This method is like `_.set` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = {};

_.setWith(object, '[0][1]', 'a', Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
value * The value to set.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) shuffle(collection) → {Array}

Description:
  • Creates an array of shuffled values, using a version of the [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle).
Source:
Since:
  • 0.1.0
Example
_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]
Parameters:
Name Type Description
collection Array | Object The collection to shuffle.
Returns:
Returns the new shuffled array.
Type
Array

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) size(collection) → {number}

Description:
  • Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.
Source:
Since:
  • 0.1.0
Example
_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7
Parameters:
Name Type Description
collection Array | Object | string The collection to inspect.
Returns:
Returns the collection size.
Type
number

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) slice(array, startopt, endopt) → {Array}

Description:
  • Creates a slice of `array` from `start` up to, but not including, `end`. **Note:** This method is used instead of [`Array#slice`](https://mdn.io/Array/slice) to ensure dense arrays are returned.
Source:
Since:
  • 3.0.0
Parameters:
Name Type Attributes Default Description
array Array The array to slice.
start number <optional>
0 The start position.
end number <optional>
array.length The end position.
Returns:
Returns the slice of `array`.
Type
Array

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) some(collection, predicateopt) → {boolean}

Description:
  • Checks if `predicate` returns truthy for **any** element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).
Source:
Since:
  • 0.1.0
Example
_.some([null, 0, 'yes', false], Boolean);
// => true

var users = [
  { 'user': 'barney', 'active': true },
  { 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some(users, { 'user': 'barney', 'active': false });
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(users, ['active', false]);
// => true

// The `_.property` iteratee shorthand.
_.some(users, 'active');
// => true
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns `true` if any element passes the predicate check, else `false`.
Type
boolean

(static) sortBy(collection, …iterateesopt) → {Array}

Description:
  • Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).
Source:
Since:
  • 0.1.0
Example
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 30 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]
Parameters:
Name Type Attributes Default Description
collection Array | Object The collection to iterate over.
iteratees function | Array:.<function()> <optional>
<repeatable>
[_.identity] The iteratees to sort by.
Returns:
Returns the new sorted array.
Type
Array

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndex(array, value) → {number}

Description:
  • Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 0.1.0
Example
_.sortedIndex([30, 50], 40);
// => 1
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy(objects, { 'x': 4 }, 'x');
// => 0
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedIndexOf(array, value) → {number}

Description:
  • This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedIndexOf([4, 5, 5, 5, 6], 5);
// => 1
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndex(array, value) → {number}

Description:
  • This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.
Source:
Since:
  • 3.0.0
Example
_.sortedLastIndex([4, 5, 5, 5, 6], 5);
// => 4
Parameters:
Name Type Description
array Array The sorted array to inspect.
value * The value to evaluate.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexBy(array, value, iterateeopt) → {number}

Description:
  • This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(objects, { 'x': 4 }, function(o) { return o.x; });
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy(objects, { 'x': 4 }, 'x');
// => 1
Parameters:
Name Type Attributes Default Description
array Array The sorted array to inspect.
value * The value to evaluate.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the index at which `value` should be inserted into `array`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedLastIndexOf(array, value) → {number}

Description:
  • This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.
Source:
Since:
  • 4.0.0
Example
_.sortedLastIndexOf([4, 5, 5, 5, 6], 5);
// => 3
Parameters:
Name Type Description
array Array The array to inspect.
value * The value to search for.
Returns:
Returns the index of the matched value, else `-1`.
Type
number

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniq(array) → {Array}

Description:
  • This method is like `_.uniq` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniq([1, 1, 2]);
// => [1, 2]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) sortedUniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.
Source:
Since:
  • 4.0.0
Example
_.sortedUniqBy([1.1, 1.2, 2.3, 2.4], Math.floor);
// => [1.1, 2.3]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
iteratee function <optional>
The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) split(stringopt, separator, limitopt) → {Array}

Description:
  • Splits `string` by `separator`. **Note:** This method is based on [`String#split`](https://mdn.io/String/split).
Source:
Since:
  • 4.0.0
Example
_.split('a-b-c', '-', 2);
// => ['a', 'b']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to split.
separator RegExp | string The separator pattern to split by.
limit number <optional>
The length to truncate results to.
Returns:
Returns the string segments.
Type
Array

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) spread(func, startopt) → {function}

Description:
  • Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like [`Function#apply`](http://www.ecma-international.org/ecma-262/7.0/#sec-function.prototype.apply). **Note:** This method is based on the [spread operator](https://mdn.io/spread_operator).
Source:
Since:
  • 3.2.0
Example
var say = _.spread(function(who, what) {
  return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
  Promise.resolve(40),
  Promise.resolve(36)
]);

numbers.then(_.spread(function(x, y) {
  return x + y;
}));
// => a Promise of 76
Parameters:
Name Type Attributes Default Description
func function The function to spread arguments over.
start number <optional>
0 The start position of the spread.
Returns:
Returns the new function.
Type
function

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) startsWith(stringopt, targetopt, positionopt) → {boolean}

Description:
  • Checks if `string` starts with the given target string.
Source:
Since:
  • 3.0.0
Example
_.startsWith('abc', 'a');
// => true

_.startsWith('abc', 'b');
// => false

_.startsWith('abc', 'b', 1);
// => true
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
target string <optional>
The string to search for.
position number <optional>
0 The position to search from.
Returns:
Returns `true` if `string` starts with `target`, else `false`.
Type
boolean

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubArray() → {Array}

Description:
  • This method returns a new empty array.
Source:
Since:
  • 4.13.0
Example
var arrays = _.times(2, _.stubArray);

console.log(arrays);
// => [[], []]

console.log(arrays[0] === arrays[1]);
// => false
Returns:
Returns the new empty array.
Type
Array

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubFalse() → {boolean}

Description:
  • This method returns `false`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubFalse);
// => [false, false]
Returns:
Returns `false`.
Type
boolean

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubObject() → {Object}

Description:
  • This method returns a new empty object.
Source:
Since:
  • 4.13.0
Example
var objects = _.times(2, _.stubObject);

console.log(objects);
// => [{}, {}]

console.log(objects[0] === objects[1]);
// => false
Returns:
Returns the new empty object.
Type
Object

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubString() → {string}

Description:
  • This method returns an empty string.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubString);
// => ['', '']
Returns:
Returns the empty string.
Type
string

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) stubTrue() → {boolean}

Description:
  • This method returns `true`.
Source:
Since:
  • 4.13.0
Example
_.times(2, _.stubTrue);
// => [true, true]
Returns:
Returns `true`.
Type
boolean

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sum(array) → {number}

Description:
  • Computes the sum of the values in `array`.
Source:
Since:
  • 3.4.0
Example
_.sum([4, 2, 8, 6]);
// => 20
Parameters:
Name Type Description
array Array The array to iterate over.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) sumBy(array, iterateeopt) → {number}

Description:
  • This method is like `_.sum` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be summed. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.sumBy(objects, function(o) { return o.n; });
// => 20

// The `_.property` iteratee shorthand.
_.sumBy(objects, 'n');
// => 20
Parameters:
Name Type Attributes Default Description
array Array The array to iterate over.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the sum.
Type
number

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) tail(array) → {Array}

Description:
  • Gets all but the first element of `array`.
Source:
Since:
  • 4.0.0
Example
_.tail([1, 2, 3]);
// => [2, 3]
Parameters:
Name Type Description
array Array The array to query.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) take(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the beginning.
Source:
Since:
  • 0.1.0
Example
_.take([1, 2, 3]);
// => [1]

_.take([1, 2, 3], 2);
// => [1, 2]

_.take([1, 2, 3], 5);
// => [1, 2, 3]

_.take([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRight(array, nopt) → {Array}

Description:
  • Creates a slice of `array` with `n` elements taken from the end.
Source:
Since:
  • 3.0.0
Example
_.takeRight([1, 2, 3]);
// => [3]

_.takeRight([1, 2, 3], 2);
// => [2, 3]

_.takeRight([1, 2, 3], 5);
// => [1, 2, 3]

_.takeRight([1, 2, 3], 0);
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
n number <optional>
1 The number of elements to take.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeRightWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': true },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(users, function(o) { return !o.active; });
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile(users, { 'user': 'pebbles', 'active': false });
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(users, ['active', false]);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) takeWhile(array, predicateopt) → {Array}

Description:
  • Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).
Source:
Since:
  • 3.0.0
Example
var users = [
  { 'user': 'barney',  'active': false },
  { 'user': 'fred',    'active': false },
  { 'user': 'pebbles', 'active': true }
];

_.takeWhile(users, function(o) { return !o.active; });
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile(users, { 'user': 'barney', 'active': false });
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(users, ['active', false]);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile(users, 'active');
// => []
Parameters:
Name Type Attributes Default Description
array Array The array to query.
predicate function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the slice of `array`.
Type
Array

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) tap(value, interceptor) → {*}

Description:
  • This method invokes `interceptor` and returns `value`. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.
Source:
Since:
  • 0.1.0
Example
_([1, 2, 3])
 .tap(function(array) {
   // Mutate input array.
   array.pop();
 })
 .reverse()
 .value();
// => [2, 1]
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns `value`.
Type
*

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'lodash.templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) template(stringopt, optionsopt) → {function}

Description:
  • Creates a compiled template function that can interpolate data properties in "interpolate" delimiters, HTML-escape interpolated data properties in "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data properties may be accessed as free variables in the template. If a setting object is given, it takes precedence over `_.templateSettings` values. **Note:** In the development build `_.template` utilizes [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) for easier debugging. For more information on precompiling templates see [lodash's custom builds documentation](https://lodash.com/custom-builds). For more information on Chrome extension sandboxes see [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
Source:
Since:
  • 0.1.0
Example
// Use the "interpolate" delimiter to create a compiled template.
var compiled = _.template('hello <%= user %>!');
compiled({ 'user': 'fred' });
// => 'hello fred!'

// Use the HTML "escape" delimiter to escape data property values.
var compiled = _.template('<b><%- value %></b>');
compiled({ 'value': '<script>' });
// => '<b>&lt;script&gt;</b>'

// Use the "evaluate" delimiter to execute JavaScript and generate HTML.
var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the internal `print` function in "evaluate" delimiters.
var compiled = _.template('<% print("hello " + user); %>!');
compiled({ 'user': 'barney' });
// => 'hello barney!'

// Use the ES template literal delimiter as an "interpolate" delimiter.
// Disable support by replacing the "interpolate" delimiter.
var compiled = _.template('hello ${ user }!');
compiled({ 'user': 'pebbles' });
// => 'hello pebbles!'

// Use backslashes to treat delimiters as plain text.
var compiled = _.template('<%= "\\<%- value %\\>" %>');
compiled({ 'value': 'ignored' });
// => '<%- value %>'

// Use the `imports` option to import `jQuery` as `jq`.
var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
compiled({ 'users': ['fred', 'barney'] });
// => '<li>fred</li><li>barney</li>'

// Use the `sourceURL` option to specify a custom sourceURL for the template.
var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
compiled(data);
// => Find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector.

// Use the `variable` option to ensure a with-statement isn't used in the compiled template.
var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
compiled.source;
// => function(data) {
//   var __t, __p = '';
//   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
//   return __p;
// }

// Use custom template delimiters.
_.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
var compiled = _.template('hello {{ user }}!');
compiled({ 'user': 'mustache' });
// => 'hello mustache!'

// Use the `source` property to inline compiled templates for meaningful
// line numbers in error messages and stack traces.
fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\
  var JST = {\
    "main": ' + _.template(mainText).source + '\
  };\
');
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The template string.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
escape RegExp <optional>
_.templateSettings.escape The HTML "escape" delimiter.
evaluate RegExp <optional>
_.templateSettings.evaluate The "evaluate" delimiter.
imports Object <optional>
_.templateSettings.imports An object to import into the template as free variables.
interpolate RegExp <optional>
_.templateSettings.interpolate The "interpolate" delimiter.
sourceURL string <optional>
'templateSources[n]' The sourceURL of the compiled template.
variable string <optional>
'obj' The data object variable name.
Returns:
Returns the compiled template function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) throttle(func, waitopt, optionsopt) → {function}

Description:
  • Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation. **Note:** If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout. If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`. See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/) for details over the differences between `_.throttle` and `_.debounce`.
Source:
Since:
  • 0.1.0
Example
// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(updatePosition, 100));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);
Parameters:
Name Type Attributes Default Description
func function The function to throttle.
wait number <optional>
0 The number of milliseconds to throttle invocations to.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
leading boolean <optional>
true Specify invoking on the leading edge of the timeout.
trailing boolean <optional>
true Specify invoking on the trailing edge of the timeout.
Returns:
Returns the new throttled function.
Type
function

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) thru(value, interceptor) → {*}

Description:
  • This method is like `_.tap` except that it returns the result of `interceptor`. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.
Source:
Since:
  • 3.0.0
Example
_('  abc  ')
 .chain()
 .trim()
 .thru(function(value) {
   return [value];
 })
 .value();
// => ['abc']
Parameters:
Name Type Description
value * The value to provide to `interceptor`.
interceptor function The function to invoke.
Returns:
Returns the result of `interceptor`.
Type
*

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) times(n, iterateeopt) → {Array}

Description:
  • Invokes the iteratee `n` times, returning an array of the results of each invocation. The iteratee is invoked with one argument; (index).
Source:
Since:
  • 0.1.0
Example
_.times(3, String);
// => ['0', '1', '2']

 _.times(4, _.constant(0));
// => [0, 0, 0, 0]
Parameters:
Name Type Attributes Default Description
n number The number of times to invoke `iteratee`.
iteratee function <optional>
_.identity The function invoked per iteration.
Returns:
Returns the array of results.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toArray(value) → {Array}

Description:
  • Converts `value` to an array.
Source:
Since:
  • 0.1.0
Example
_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted array.
Type
Array

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toFinite(value) → {number}

Description:
  • Converts `value` to a finite number.
Source:
Since:
  • 4.12.0
Example
_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted number.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toInteger(value) → {number}

Description:
  • Converts `value` to an integer. **Note:** This method is loosely based on [`ToInteger`](http://www.ecma-international.org/ecma-262/7.0/#sec-tointeger).
Source:
Since:
  • 4.0.0
Example
_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLength(value) → {number}

Description:
  • Converts `value` to an integer suitable for use as the length of an array-like object. **Note:** This method is based on [`ToLength`](http://ecma-international.org/ecma-262/7.0/#sec-tolength).
Source:
Since:
  • 4.0.0
Example
_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toLower(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to lower case just like [String#toLowerCase](https://mdn.io/toLowerCase).
Source:
Since:
  • 4.0.0
Example
_.toLower('--Foo-Bar--');
// => '--foo-bar--'

_.toLower('fooBar');
// => 'foobar'

_.toLower('__FOO_BAR__');
// => '__foo_bar__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the lower cased string.
Type
string

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toNumber(value) → {number}

Description:
  • Converts `value` to a number.
Source:
Since:
  • 4.0.0
Example
_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2
Parameters:
Name Type Description
value * The value to process.
Returns:
Returns the number.
Type
number

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPath(value) → {Array}

Description:
  • Converts `value` to a property path array.
Source:
Since:
  • 4.0.0
Example
_.toPath('a.b.c');
// => ['a', 'b', 'c']

_.toPath('a[0].b.c');
// => ['a', '0', 'b', 'c']
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the new property path array.
Type
Array

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toPlainObject(value) → {Object}

Description:
  • Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted plain object.
Type
Object

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toSafeInteger(value) → {number}

Description:
  • Converts `value` to a safe integer. A safe integer can be compared and represented correctly.
Source:
Since:
  • 4.0.0
Example
_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted integer.
Type
number

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toString(value) → {string}

Description:
  • Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.
Source:
Since:
  • 4.0.0
Example
_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'
Parameters:
Name Type Description
value * The value to convert.
Returns:
Returns the converted string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) toUpper(stringopt) → {string}

Description:
  • Converts `string`, as a whole, to upper case just like [String#toUpperCase](https://mdn.io/toUpperCase).
Source:
Since:
  • 4.0.0
Example
_.toUpper('--foo-bar--');
// => '--FOO-BAR--'

_.toUpper('fooBar');
// => 'FOOBAR'

_.toUpper('__foo_bar__');
// => '__FOO_BAR__'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to convert.
Returns:
Returns the upper cased string.
Type
string

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) transform(object, iterateeopt, accumulatoropt) → {*}

Description:
  • An alternative to `_.reduce`; this method transforms `object` to a new `accumulator` object which is the result of running each of its own enumerable string keyed properties thru `iteratee`, with each invocation potentially mutating the `accumulator` object. If `accumulator` is not provided, a new object with the same `[[Prototype]]` will be used. The iteratee is invoked with four arguments: (accumulator, value, key, object). Iteratee functions may exit iteration early by explicitly returning `false`.
Source:
Since:
  • 1.3.0
Example
_.transform([2, 3, 4], function(result, n) {
  result.push(n *= n);
  return n % 2 == 0;
}, []);
// => [4, 9]

_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) {
  (result[value] || (result[value] = [])).push(key);
}, {});
// => { '1': ['a', 'c'], '2': ['b'] }
Parameters:
Name Type Attributes Default Description
object Object The object to iterate over.
iteratee function <optional>
_.identity The function invoked per iteration.
accumulator * <optional>
The custom accumulator value.
Returns:
Returns the accumulated value.
Type
*

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trim(stringopt, charsopt) → {string}

Description:
  • Removes leading and trailing whitespace or specified characters from `string`.
Source:
Since:
  • 3.0.0
Example
_.trim('  abc  ');
// => 'abc'

_.trim('-_-abc-_-', '_-');
// => 'abc'

_.map(['  foo  ', '  bar  '], _.trim);
// => ['foo', 'bar']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimEnd(stringopt, charsopt) → {string}

Description:
  • Removes trailing whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimEnd('  abc  ');
// => '  abc'

_.trimEnd('-_-abc-_-', '_-');
// => '-_-abc'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) trimStart(stringopt, charsopt) → {string}

Description:
  • Removes leading whitespace or specified characters from `string`.
Source:
Since:
  • 4.0.0
Example
_.trimStart('  abc  ');
// => 'abc  '

_.trimStart('-_-abc-_-', '_-');
// => 'abc-_-'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to trim.
chars string <optional>
whitespace The characters to trim.
Returns:
Returns the trimmed string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) truncate(stringopt, optionsopt) → {string}

Description:
  • Truncates `string` if it's longer than the given maximum string length. The last characters of the truncated string are replaced with the omission string which defaults to "...".
Source:
Since:
  • 4.0.0
Example
_.truncate('hi-diddly-ho there, neighborino');
// => 'hi-diddly-ho there, neighbo...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': ' '
});
// => 'hi-diddly-ho there,...'

_.truncate('hi-diddly-ho there, neighborino', {
  'length': 24,
  'separator': /,? +/
});
// => 'hi-diddly-ho there...'

_.truncate('hi-diddly-ho there, neighborino', {
  'omission': ' [...]'
});
// => 'hi-diddly-ho there, neig [...]'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to truncate.
options Object <optional>
{} The options object.
Properties
Name Type Attributes Default Description
length number <optional>
30 The maximum string length.
omission string <optional>
'...' The string to indicate text is omitted.
separator RegExp | string <optional>
The separator pattern to truncate to.
Returns:
Returns the truncated string.
Type
string

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unary(func) → {function}

Description:
  • Creates a function that accepts up to one argument, ignoring any additional arguments.
Source:
Since:
  • 4.0.0
Example
_.map(['6', '8', '10'], _.unary(parseInt));
// => [6, 8, 10]
Parameters:
Name Type Description
func function The function to cap arguments for.
Returns:
Returns the new capped function.
Type
function

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) unescape(stringopt) → {string}

Description:
  • The inverse of `_.escape`; this method converts the HTML entities `&`, `<`, `>`, `"`, and `'` in `string` to their corresponding characters. **Note:** No other HTML entities are unescaped. To unescape additional HTML entities use a third-party library like [_he_](https://mths.be/he).
Source:
Since:
  • 0.6.0
Example
_.unescape('fred, barney, &amp; pebbles');
// => 'fred, barney, & pebbles'
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to unescape.
Returns:
Returns the unescaped string.
Type
string

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniq(array) → {Array}

Description:
  • Creates a duplicate-free version of an array, using [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.
Source:
Since:
  • 0.1.0
Example
_.uniq([2, 1, 2]);
// => [2, 1]
Parameters:
Name Type Description
array Array The array to inspect.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqBy(array, iterateeopt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument: (value).
Source:
Since:
  • 4.0.0
Example
_.uniqBy([2.1, 1.2, 2.3], Math.floor);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
Parameters:
Name Type Attributes Default Description
array Array The array to inspect.
iteratee function <optional>
_.identity The iteratee invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqWith(array, comparatoropt) → {Array}

Description:
  • This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).
Source:
Since:
  • 4.0.0
Example
var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(objects, _.isEqual);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]
Parameters:
Name Type Attributes Description
array Array The array to inspect.
comparator function <optional>
The comparator invoked per element.
Returns:
Returns the new duplicate free array.
Type
Array

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) uniqueId(prefixopt) → {string}

Description:
  • Generates a unique ID. If `prefix` is given, the ID is appended to it.
Source:
Since:
  • 0.1.0
Example
_.uniqueId('contact_');
// => 'contact_104'

_.uniqueId();
// => '105'
Parameters:
Name Type Attributes Default Description
prefix string <optional>
'' The value to prefix the ID with.
Returns:
Returns the unique ID.
Type
string

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unset(object, path) → {boolean}

Description:
  • Removes the property at `path` of `object`. **Note:** This method mutates `object`.
Source:
Since:
  • 4.0.0
Example
var object = { 'a': [{ 'b': { 'c': 7 } }] };
_.unset(object, 'a[0].b.c');
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };

_.unset(object, ['a', '0', 'b', 'c']);
// => true

console.log(object);
// => { 'a': [{ 'b': {} }] };
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to unset.
Returns:
Returns `true` if the property is deleted, else `false`.
Type
boolean

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzip(array) → {Array}

Description:
  • This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.
Source:
Since:
  • 1.2.0
Example
var zipped = _.zip(['a', 'b'], [1, 2], [true, false]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]
Parameters:
Name Type Description
array Array The array of grouped elements to process.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) unzipWith(array, iterateeopt) → {Array}

Description:
  • This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).
Source:
Since:
  • 3.8.0
Example
var zipped = _.zip([1, 2], [10, 20], [100, 200]);
// => [[1, 10, 100], [2, 20, 200]]

_.unzipWith(zipped, _.add);
// => [3, 30, 300]
Parameters:
Name Type Attributes Default Description
array Array The array of grouped elements to process.
iteratee function <optional>
_.identity The function to combine regrouped values.
Returns:
Returns the new array of regrouped elements.
Type
Array

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) update(object, path, updater) → {Object}

Description:
  • This method is like `_.set` except that accepts `updater` to produce the value to set. Use `_.updateWith` to customize `path` creation. The `updater` is invoked with one argument: (value). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0
Parameters:
Name Type Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) updateWith(object, path, updater, customizeropt) → {Object}

Description:
  • This method is like `_.update` except that it accepts `customizer` which is invoked to produce the objects of `path`. If `customizer` returns `undefined` path creation is handled by the method instead. The `customizer` is invoked with three arguments: (nsValue, key, nsObject). **Note:** This method mutates `object`.
Source:
Since:
  • 4.6.0
Example
var object = {};

_.updateWith(object, '[0][1]', _.constant('a'), Object);
// => { '0': { '1': 'a' } }
Parameters:
Name Type Attributes Description
object Object The object to modify.
path Array | string The path of the property to set.
updater function The function to produce the updated value.
customizer function <optional>
The function to customize assigned values.
Returns:
Returns `object`.
Type
Object

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) values(object) → {Array}

Description:
  • Creates an array of the own enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 0.1.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.values(new Foo);
// => [1, 2] (iteration order is not guaranteed)

_.values('hi');
// => ['h', 'i']
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) valuesIn(object) → {Array}

Description:
  • Creates an array of the own and inherited enumerable string keyed property values of `object`. **Note:** Non-object values are coerced to objects.
Source:
Since:
  • 3.0.0
Example
function Foo() {
  this.a = 1;
  this.b = 2;
}

Foo.prototype.c = 3;

_.valuesIn(new Foo);
// => [1, 2, 3] (iteration order is not guaranteed)
Parameters:
Name Type Description
object Object The object to query.
Returns:
Returns the array of property values.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) words(stringopt, patternopt) → {Array}

Description:
  • Splits `string` into an array of its words.
Source:
Since:
  • 3.0.0
Example
_.words('fred, barney, & pebbles');
// => ['fred', 'barney', 'pebbles']

_.words('fred, barney, & pebbles', /[^, ]+/g);
// => ['fred', 'barney', '&', 'pebbles']
Parameters:
Name Type Attributes Default Description
string string <optional>
'' The string to inspect.
pattern RegExp | string <optional>
The pattern to match words.
Returns:
Returns the words of `string`.
Type
Array

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) wrap(value, wrapperopt) → {function}

Description:
  • Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.
Source:
Since:
  • 0.1.0
Example
var p = _.wrap(_.escape, function(func, text) {
  return '<p>' + func(text) + '</p>';
});

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'
Parameters:
Name Type Attributes Default Description
value * The value to wrap.
wrapper function <optional>
identity The wrapper function.
Returns:
Returns the new function.
Type
function

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObject(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.
Source:
Since:
  • 0.4.0
Example
_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object

(static) zipObjectDeep(propsopt, valuesopt) → {Object}

Description:
  • This method is like `_.zipObject` except that it supports property paths.
Source:
Since:
  • 4.1.0
Example
_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }
Parameters:
Name Type Attributes Default Description
props Array <optional>
[] The property identifiers.
values Array <optional>
[] The property values.
Returns:
Returns the new object.
Type
Object